cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Chiral sine-Gordon model
Creators: name: Yanagisawa, Takashi
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We investigate the chiral sine-Gordon model using the renormalization group method. The chiral sine-Gordon model is a model for $G$-valued fields and describes a new class of phase transitions, where $G$ is a compact Lie group. We show that the model is renormalizable by means of a perturbation expansion and we derive beta functions of the renormalization group theory. The coefficients of beta functions are represented by the Casimir invariants. The model contains both asymptotically free and ultraviolet strong coupling regions. The beta functions have a zero which is a bifurcation point that divides the parameter space into two regions; they are the weak coupling region and the strong coupling region. A large-$N$ model is also considered. This model is reduced to the conventional sine-Gordon model that describes the Kosterlitz-Thouless transition near the fixed point. In the strong-coupling limit, the model is reduced to a $U(N)$ matrix model.
description: 6 pages; dimension d=2-epsilon
Local Boron Doping for p-type PERL Silicon Solar Cells Fabricated by Laser Processing of Doped Silicon Nanoparticle Paste
Creators: name: Jäger, U.
name: Wolf, A.
name: Wufka, C.
name: Mack, S.
name: Tomizawa, Y.
name: Imamura, T.
name: Soeda, M.
name: Ikeda, Y.
name: Shiro, T.
Publisher: name: WIP
Year: 2014
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 1111-1115
description: We present the fabrication of local boron doping for local contacts for p-type PERL solar cells. A
boron doped silicon nanoparticle paste is printed onto the passivated rear side of the wafer and is locally diffused into
the wafer by an adapted laser process. Thus a local p+ doping is formed and the passivation is opened in a single
processing step. After a description of the process and the properties of the local boron doping, fabricated solar cells
are discussed. A maximum conversion efficiency of 20.0% is achieved for PERL type solar cells on 6-inch MCz-Si
wafers. High fill factors above 79% and high open circuit voltages above 650 mV are observed, highlighting the
effectiveness of the local back surface field underneath the rear side point contacts.
UniSAFE: University Of Turin – institutional policy to address gender-based violence
Creators: name: Andreska, Zuzana
name: Huck, Averil
name: Linkova, Marcela
Publisher: name: Zenodo
Year: 2022
Subjects: Gender based-violence
policy framework
gender+
institutional policy

description: UniSAFE has mapped the policies and measures to address and combat GBV in 48 universities and research organisations in 15 European countries. For each institution, the team created Vignettes which present national context, institutional policy, training, role in knowledge production, content of the policy, institutional procedure and implementation of the policy.
Holographic entanglement entropy for hollow cones and banana shaped regions
Creators: name: Dorn, Harald
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We consider banana shaped regions as examples of compact regions, whose boundary has two conical singularities. Their regularised holographic entropy is calculated with all divergent as well as finite terms. The coefficient of the squared logarithmic divergence, also in such a case with internally curved boundary, agrees with that calculated in the literature for infinite circular cones with their internally flat boundary. For the otherwise conformally invariant coefficient of the ordinary logarithmic divergence an anomaly under exceptional conformal transformations is observed. The construction of minimal submanifolds, needed for the entanglement entropy of cones, requires fine-tuning of Cauchy data. Perturbations of such fine-tuning leads to solutions relevant for hollow cones. The divergent parts for the entanglement entropy of hollow cones are calculated. Increasing the difference between the opening angles of their outer and inner boundary, one finds a transition between connected solutions for small differences to disconnected solutions for larger ones.
description: 22 pages, 6 figures, comment added after eq. (71), version as appeared in JHEP
Understanding inverse metallicity gradients in galactic discs as a consequence of inside-out formation
Creators: name: Schönrich, Ralph
name: McMillan, Paul
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The early stages of a galaxy's evolution leave an imprint on its metallicity distribution. We discuss the origins and evolution of radial metallicity gradients in discs of spiral galaxies using an analytical chemical evolution model. We explain how radial metallicity gradients in stellar populations are determined by three factors: the radial metallicity profile of the star-forming ISM, radial changes in the star-formation history (in particular inside-out formation), and radial mixing of stars. Under reasonable assumptions, inside-out formation steepens the negative ISM metallicity gradient, but contributes positively to the stellar metallicity gradient, up to inverting the metallicity profile to a positive d[Fe/H]/dR. This reconciles steep negative d[Fe/H]/dR in some high redshift galaxies to generally flatter gradients in local observations. We discuss the evidence for inverse radial metallicity gradients (positive d[X/H]/dR) at high redshifts and the inverse relationship between azimuthal velocity and the metallicity (positive dV_ϕ/d[Fe/H]) of stars for the Milky Way's thick disc. The former can be achieved by high central gas-loss rates and re-distribution processes, e.g. re-accretion of enriched material in conjunction with inside-out formation, and near-disc galactic fountaining. For the Milky Way thick disc, we show that the positive dV_ϕ/d[Fe/H] correlation points to comparable timescales for inside-out formation, initial metal enrichment and SNIa enrichment. We argue that the original ISM metallicity gradient could be inferred with better data from the high-metallicity tail of the alpha enhanced population. Including inside-out formation in our models changes the local vertical metallicity gradient by about -0.2dex/kpc, in line with local measurements.
description: 22 pages, 16 figures, published as MNRAS 467, 1154
Fundamental gaps of the Gross-Pitaevskii equation with repulsive interaction
Creators: name: Bao, Weizhu
name: Ruan, Xinran
Publisher: name: arXiv
Year: 2015
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 35B40, 35P30, 35Q55, 65N25

description: We study asymptotically and numerically the fundamental gaps (i.e. the difference between the first excited state and the ground state) in energy and chemical potential of the Gross-Pitaevskii equation (GPE) -- nonlinear Schrodinger equation with cubic nonlinearity -- with repulsive interaction under different trapping potentials including box potential and harmonic potential. Based on our asymptotic and numerical results, we formulate a gap conjecture on the fundamental gaps in energy and chemical potential of the GPE on bounded domains with the homogeneous Dirichlet boundary condition, and in the whole space with a convex trapping potential growing at least quadratically in the far field. We then extend these results to the GPE on bounded domains with either the homogeneous Neumann boundary condition or periodic boundary condition.
description: 26 pages, 16 figures
The three-dimensional $O(n)$ $ϕ^4$ model on a strip with free boundary conditions: exact results for a nontrivial dimensional crossover in the limit $n\to\infty$
Creators: name: Diehl, H. W.
name: Rutkevich, Sergei B.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Recent exact $n\to\infty$ results for critical Casimir forces of the $O(n)$ $ϕ^4$ model on a three-dimensional strip bounded by two planar free surfaces at a distance $L$ are surveyed. This model has long-range order below the bulk critical temperature $T_c$ if $L=\infty$, but remains disordered for all $T>0$ when $L
description: Invited talk at MQFT2015, pdf-Latex, 26 pages
WIMP detection and slow ion dynamics in carbon nanotube arrays
Creators: name: Cavoto, G.
name: Cirillo, E. N. M.
name: Cocina, F.
name: Ferretti, J.
name: Polosa, A. D.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Large arrays of aligned carbon nanotubes (CNTs), open at one end, could be used as target material for the directional detection of weakly interacting dark matter particles (WIMPs). As a result of a WIMP elastic scattering on a CNT, a carbon ion might be injected in the body of the array and propagate through multiple collisions within the lattice. The ion may eventually emerge from the surface with open end CNTs, provided that its longitudinal momentum is large enough to compensate energy losses and its transverse momentum approaches the channeling conditions in a single CNT. Therefore, the angle formed between the WIMP wind apparent orientation and the direction of parallel carbon nanotube axes must be properly chosen. We focus on very low ion recoil kinetic energies, related to low mass WIMPs (~ 10 GeV) where most of the existing experiments have low sensitivity. Relying on some exact results on two-dimensional lattices of circular obstacles, we study the low energy ion motion in the transverse plane with respect to CNT directions. New constraints are obtained on how to devise the CNT arrays to maximize the detection efficiency.
description: 10 pages, 12 figures, comments and clarifications added, to appear in EPJC
A Unified Approach for Modeling Fundamental Characteristics of Highly Efficient Silicon Based p-n Junction and Heterojunction Solar Cells
Creators: name: Sachenko, A.V.
name: Kostylyov, V.P.
name: Kulish, M.R.
name: Sokolovskyi, I.O.
name: Shkrebtii / Chkrebtii, A.
name: Gaspari, F.
Publisher: name: WIP
Year: 2014
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Characterisation and Modelling

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 1116-1119
description: We developed and applied physically transparent and efficient formalism of photoconversion in single
junction solar cells. The photoconversion efficiency  of high-efficiency silicon based solar cells (SCs) is analyzed
focusing on the role of combined surface recombinations at the illuminated and back surfaces with its combined
velocity Ss. Both silicon based p-n junction SCs and –Si:H–Si or –SiC:H–Si heterojunctions (the so-called
heterojunction with intrinsic thin layer (HIT) structures) based SCs are studied within the same general approach. It is
shown that the open circuit voltage Voc increase due to an additional contribution from the back surface is the
common and essential feature of the photoconversion and high efficiency in the above SCs. Equations that
comprehensively describe the photoconversion processes were derived and solved. This includes the most basic
mechanisms of recombination: Shockley-Read-Hall (SRH) recombination, radiative recombination, surface
recombination, recombination in the space charge region (SCR) and band-to-band Auger recombination. Calculated
photoconversion efficiency  of the above systems were compared to the experimental values at AM1.5 condition for
highly efficient Si based SCs with  = 25% for p-n junction based systems,  = 24.7% for –Si:H–Si HIT structures
and  = 20.3% for -SixC1-x:H-Si SCs. Comparison of theory and experiment allowed us to estimate the combined
surface recombination velocity Ss, which was minimized in the above solar cells to achieve record high
photoconversion. Our calculated maximum efficiency max for the silicon based SCs also fits very well the max
calculated using more complex formalisms, available in the literature, thus confirming practicality of our theoretical
results.
The Influence of a Low Doping Concentration Emitter on the Performance of Selective Emitter Silicon Solar Cells
Creators: name: Ye, F.
name: Deng, W.
name: Chen, D.
name: Chen, Y.
name: Dong, J.
name: Ding, J.
name: Yuan, N.
name: Feng, Z.
name: Verlinden, P.J.
Publisher: name: WIP
Year: 2014
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 1069-1071
description: For many years, selective emitter (SE) silicon solar cells have demonstrated higher efficiency than homogeneous emitter (HE) solar cells. SE solar cells are now commonly manufactured in industrial mass production. The efficiency gain is however limited by the practical sheet resistance attainable for heavily and lightly doped emitters. An optimized two-step diffusion process for making SE solar cells with a low doping concentration emitter is investigated and compared to the conventional one-step diffusion. An emitter with sheet resistance of 60Ω/ was diffused by a two-step diffusion process. An emitter with sheet resistance of 65Ω/ as a baseline reference was fabricated and compared. After inkjet printing of mask paste and an etch-back process, a sheet resistance of 140Ω/ was obtained for these two types of diffusion. The etching rate for both emitters was studied. The total saturation current density, J0,total, for an optimized emitter shows reduction of about 21 fA/cm2 compared to that of the reference emitter. This reduction in J0e corresponds to an average Voc increase of about 3.9 mV, as demonstrated experimentally. The conversion efficiency of solar cells with the optimized emitter increases approximately by 0.1%abs compared to the reference cell. Internal quantum efficiency and reflectance were compared for these two types of SE solar cells.
Basic circuit compilation techniques for an ion-trap quantum machine
Creators: name: Maslov, Dmitri
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Emerging Technologies (cs.ET)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We study the problem of compilation of quantum algorithms into optimized physical-level circuits executable in a quantum information processing (QIP) experiment based on trapped atomic ions. We report a complete strategy: starting with an algorithm in the form of a quantum computer program, we compile it into a high-level logical circuit that goes through multiple stages of decomposition into progressively lower-level circuits until we reach the physical execution-level specification. We skip the fault-tolerance layer, as it is not within the scope of this work. The different stages are structured so as to best assist with the overall optimization while taking into account numerous optimization criteria, including minimizing the number of expensive two-qubit gates, minimizing the number of less expensive single-qubit gates, optimizing the runtime, minimizing the overall circuit error, and optimizing classical control sequences. Our approach allows a trade-off between circuit runtime and quantum error, as well as to accommodate future changes in the optimization criteria that may likely arise as a result of the anticipated improvements in the physical-level control of the experiment.
description: 18 pages
Effect of Oxygen during Thermal Annealing on the Electrical and Optical Properties of Sputter Deposited Al-Doped ZnO Films for Heterojunction Solar Cell Application
Creators: name: Gorgulla, A.
name: Brinkmann, N.
name: Skorka, D.
name: Hahn, G.
name: Terheiden, B.
Publisher: name: WIP
Year: 2014
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 1076-1080
description: The influence of oxygen during short post deposition annealing on Al-doped zinc oxide (AZO) films
for heterojunction solar cells grown by sputter deposition is investigated in terms of their electrical, optical and
structural properties. AZO films were annealed for 4 min at 300°C and 450°C in ambient air and N2 atmosphere. It
has been shown, that at 450°C the elimination of oxygen during annealing allows an increase in carrier concentration
and reduction of the sheet resistance of AZO films four times higher than annealing in ambient air. This effect has not
been observed for annealing temperatures below 300°C, where annealing in ambient air proved to have superior
influence on the electrical properties. The optical bandgap of all annealed samples was enlarged and for an annealing
temperature of 450°C the optical transmission weighted by ASTM G173-03 solar spectrum from 300 to 1100 nm was
increased to over 80%. The changes observed in all samples were primarily explained by means of oxygen
chemisorption and desorption processes. It is concluded, that oxygen plays an important role in the improvement of
electrical and optical properties of AZO thin films during thermal annealing.
Effect of Rear Surface Morphology on Al-BSF Uniformity of Silicon Solar Cells
Creators: name: Dong, D.
name: Deng, W.
name: Chen, D.
name: Chen, Y.
name: Ye, F.
name: Liu, B.
name: Feng, Z.
name: Verlinden, P.J.
Publisher: name: WIP
Year: 2014
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 1059-1061
description: The quality of screen printed Al Back Surface Field (Al-BSF) on alkaline textured, polished or acidtextured
surface was investigated. Al paste was screen-printed on a full rear surface of silicon wafers and Al-BSF was
formed during firing process in a belt furnace. The morphology of the formed Al-BSFs was observed by Scanning
Electron Microscopy (SEM). Compared to an alkaline textured surface, the Si/BSF interface on a polished surface is
smoother, and the Al-BSF is continuous. J0 was measured by photoconductivity decay (PCD) and the J0,BSF of
different kinds of rear surfaces were compared. It was observed that J0,BSF is strongly affected by Al-BSF uniformity.
J0,BSF of polished surfaces is about 40fA/cm2 less than J0,BSF of alkaline textured surfaces. Through PC1D simulation,
the increase in cell efficiency was calculated to be about 0.08% absolute due to the decrease in J0,BSF.
Background independent noncommutative gravity from Fedosov quantization of endomorphism bundle
Creators: name: Dobrski, Michal
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Model of noncommutative gravity is constructed by means of Fedosov deformation quantization of endomorphism bundle. The fields describing noncommutativity -- symplectic form and symplectic connection -- are dynamical, and the resulting theory is completely coordinate covariant and background independent. Its interpretation in terms of Seiberg-Witten map is provided. Also, new action for ordinary (commutative) general relativity is given, which in the present context appears as a commutative limit of noncommutative theory.
description: 22 pages, section 3.2 reworked, various minor corrections. (This is an author-created, un-copyedited version of an article accepted for publication in Clasical and Quantum Gravity)
Effect of Corona Charged SiNx-Coated p-Type Silicon Surfaces on Effective Lifetime After Belt Furnace Annealing
Creators: name: Lu, P.H.D.
name: Hamer, P.G.
name: Lennon, A.
name: Wenham, S.
Publisher: name: WIP
Year: 2014
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 1092-1095
description: Previous studies have shown that under a positive external electric field, hydrogen can penetrate further
in p-type silicon compared to when no electric field is present or when a negative electric field is applied. This paper
reports on experiments where silicon nitride layers, formed on p-type silicon surfaces, were corona-charged before
belt furnace annealing, to simulate different electric field conditions. Injection-dependent lifetime data showed that
moderate positive corona charging can result in a ~ 60% increase in effective lifetime at 0.1 sun after annealing,
where only a 30% increase is observed in the absence of the additional charge before annealing and decreases were
observed for applied negative charges. The changes in effective lifetime were attributed to increased bulk lifetimes
with the saturation current density associated with the surfaces estimated to increase by ~ 10% after annealing and
not being very sensitive to applied corona charge.
Sandwiched Ultra Thin Silver Instead of Nanoparticles as an Alternative Broadband Anti-Reflection Coating for c-Si Solar Cell Applications
Creators: name: Singh, H.K.
name: Sharma, P.
name: Singh Solanki, C.S.
Publisher: name: WIP
Year: 2014
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 1036-1040
description: Dielectric-metal-dielectric sandwiched structure as an alternative device geometry for minimizing the reflection in context of c-Si solar cell application has been explored along with nanoparticle based reflection minimization concept. The study suggests that Ag nanoparticles are very good in minimizing reflection in infrared wavelength region but there is high reflection in UV-Vis region which is the main implication for its use for c-Si based solar cell application. The high reflection in UVVis region for nanoparticle based anti-reflection structure has been correlated with calculated backscattering from nanoparticles as per Mie solution of Maxwell equations for scattering from small particles. The alternate solution for minimizing the reflection from c-Si solar cell front surface is shown using dielectric-metal-dielectric sandwiched structure (SiNx-Ag-SiNx). For the sandwiched structure, the weighted total reflectance for wavelength range 300 nm- 1200 nm is 7.2 % which is 48 % lesser than standard 80 nm silicon nitride (SiNx) based anti-reflection device structure for non-textured Si surface which gives 13.8 %. The results suggest that the dielectric-metal-dielectric sandwiched structure is more promising than the nanoparticle based device structure for reflection minimization in broadband wavelength range (300 nm- 1200 nm). And this can give much better anti reflection (AR) property than standard SiNx based ARC on non textured Si surface which is more relevant for thin c-Si based solar cells application where tradition texturing may not be promising.
Investigating Effects of Junction Area on Open Circuit Voltage of Silicon Solar Cells
Creators: name: An, X.
name: Teng, P.
name: Mehrvarz, H.
name: To, A.
name: Barnett, A.
Publisher: name: WIP
Year: 2014
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 1041-1043
description: A high voltage silicon solar cell based on a limited area p-n junction as the emitter and rear point contact scheme is proposed. In this work, simplified test structures on planar wafers with a rudimentary front metal grid are fabricated to demonstrate the potential of such design to enhance cell open circuit voltage (Voc) above the limit for a full-area emitter solar cell. Photo-conductance decay (PCD) and photoluminescence (PL) measurements have confirmed lower dark saturation current contribution from the emitter (I0e) in the test structures than their full-area emitter counterparts. The finished solar cells, although exhibiting Voc losses caused by I0 at the p-type front surface and in the contact regions, have demonstrated the potential of limited junction area as a means to increase Voc above 710mV. To fully deliver the benefit of reduction in I0e to the final device, recombination at the surface regions will need to be further decreased.
Excellent Passivation Effect on n-Type c-Si Surface Using Low Cost Liquid Source SiO2
Creators: name: Nagayoshi, H.
name: Hagiwara, C.
Publisher: name: WIP
Year: 2014
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 1000-1002
description: An excellent passivation effect in N-type wafer was obtained using liquid source SiO2 prepared from Perhydropolysilazane(PHPS) with the combination of hot steam post annealing. The passivation property was estimated by effective lifetime, interface state density (Dit) and surface recombination velocity calculated by SRH model. The Dit of the sample after the hot steam annealing at 600C was around 1x1012cm2, though the effective lifetime reached to higher value than the chemical passivation using 1 % quinhydron methanol solution. On the other hand samples annealed in air showed much lower value. The film after the hot steam annealing has a large number of positive charges, which might improve the effective lifetime as a field effect passivation. Regarding the long term stability, the samples showed initial lifetime degradation, though it maintained ms order of lifetime at room temperature.
Fluid Wrap Around during Wet Chemical Single Side Treatments
Creators: name: Richter, M.
name: Narayanan, S.
name: Hain, A.
name: Zimmer, M.
name: Rentsch, J.
name: Reinecke, H.
Publisher: name: WIP
Year: 2014
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 1062-1068
description: Single sided etching is commonly used for processing solar cells. As with all single sided processes
using wet etching solutions, fluid wrap around appears. This paper investigates this effect in two ways. Different
experimental setups will be shown and described including results and theories concerning the fluid wrap around. It
can be proven, that bursting bubbles caused by etching support the fluid wrap around as well as some additives and
surface morphologies. Additionally, surface tension, surface energy and surface morphologies can be found as
influencing factors. Further investigations for better understanding of the fluid wrap around will be described.
Competing orders and topology in the global phase diagram of pyrochlore iridates
Creators: name: Goswami, Pallab
name: Roy, Bitan
name: Sarma, Sankar Das
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Strong electronic interactions and spin orbit coupling can be conducive for realizing novel broken symmetry phases supporting quasiparticles with nontrivial band topology. 227 pyrochlore iridates provide a suitable material platform for studying such emergent phenomena where both topology and competing orders play important roles. In contrast to the most members of this material class, which are thought to display "all-in all-out" (AIAO) type magnetically ordered low-temperature insulating ground states, Pr$_2$Ir$_2$O$_7$ remains metallic while exhibiting "spin ice" (SI) correlations at low temperatures. Additionally, this is the only 227 iridate compound, which exhibits a large anomalous Hall effect (AHE) along [1,1,1] direction below 1.5 K, without possessing any measurable magnetic moment. By focusing on the normal state of 227 iridates, described by a parabolic semimetal with quadratic band touching, we use renormalization group analysis, mean-field theory, and phenomenological Landau theory as three complementary methods to construct a global phase diagram in the presence of generic local interactions among itinerant electrons of Ir ions. While the global phase diagram supports several competing multipolar orders, motivated by the phenomenology of 227 iridates we particularly emphasize the competition between AIAO and SI orders and how it can cause a mixed phase with "three-in one-out" (3I1O) spin configurations. In terms of topological properties of Weyl quasiparticles of the 3I1O state, we provide an explanation for the magnitude and the direction of the observed AHE in Pr$_2$Ir$_2$O$_7$. We propose a strain induced enhancement of the onset temperature for AHE in thin films of Pr$_2$Ir$_2$O$_7$ and additional experiments for studying competing orders in the vicinity of the metal-insulator transition.
description: 25 pages, 11 Figures; replaced with the version published by Phys. Rev. B
Influence of a-Si: H / c-Si Interface Properties on Performance of Hetero-Junction Back Contact Si Solar Cells
Creators: name: Okamoto, C.
name: Asano, N.
name: Hieda, T.
name: Nakamura, J.
name: Suganuma, R.
name: Tadokoro, H.
name: Kobayashi, M.
name: Matsumoto, Y.
name: Nakamura, K.
Publisher: name: WIP
Year: 2014
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 959-961
description: The purpose of this work is to investigate the passivation effect of hydrogenated amorphous silicon
(a-Si:H) deposited on crystalline silicon (c-Si) by PECVD changing with a hydrogen dilution ratio and an applied
RF power. We also applied this work to high efficiency Hetero-Junction Back Contact Si Solar Cells (HBC) cell.
We evaluated the passivation quality of a-Si:H both on flat structure (100) and on textured structure (111) Cz
wafer surface, where the minority career lifetime was measured by -PCD technique. The results show that the
passivation ability on flat structure (100) surface had strong dependence on a H2/SiH4 ratio and a RF power, on
the other hand, less dependence was shown on textured surface (111). The Transmission electron microscope
(TEM) observation of a-Si:H demonstrates that crystal grains were formed in a-Si:H film for worse passivation. It
was found that a-Si:H is more easily to crystallize on flat structure (100) surface than on textured surface (111).
We utilized these findings to achieve 24.9% efficiency by HBC structure cell.
Vacancy-induced low-energy states in undoped graphene
Creators: name: Sanyal, Sambuddha
name: Damle, Kedar
name: Motrunich, Olexei I.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We demonstrate that a nonzero concentration $n_v$ of static, randomly-placed vacancies in graphene leads to a density $w$ of zero-energy quasiparticle states at the band-center $ε=0$ within a tight-binding description with nearest-neighbour hopping $t$ on the honeycomb lattice. We show that $w$ remains generically nonzero in the compensated case (exactly equal number of vacancies on the two sublattices) even in the presence of hopping disorder, and depends sensitively on $n_v$ and correlations between vacancy positions. For low, {\em but not-too-low} $|ε|/t$ in this compensated case, we show that the density of states (DOS) $ρ(ε)$ exhibits a strong divergence of the form $ρ_{\rm 1D}(ε) \sim |ε|^{-1}/ [\log(t/|ε|)]^{(y+1)} $, which crosses over to the universal low-energy asymptotic form expected on symmetry grounds $ρ_{\rm GW}(ε) \sim |ε|^{-1}e^{-b[\log(t/|ε|)]^{2/3} }$ below a crossover scale $ε_c \ll t$. $ε_c$ is found to decrease rapidly with decreasing $n_v$, while $y$ decreases much more slowly.
description: revised in response to referee reports
Coherent transfer of electron spin correlations assisted by dephasing noise
Creators: name: Nakajima, Takashi
name: Delbecq, Matthieu R.
name: Otsuka, Tomohiro
name: Amaha, Shinichi
name: Yoneda, Jun
name: Noiri, Akito
name: Takeda, Kenta
name: Allison, Giles
name: Ludwig, Arne
name: Wieck, Andreas D.
name: Hu, Xuedong
name: Nori, Franco
name: Tarucha, Seigo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum coherence of superposed states, especially of entangled states, is indispensable for many quantum technologies. However, it is vulnerable to environmental noises, posing a fundamental challenge in solid-state systems including spin qubits. Here we show a scheme of entanglement engineering where pure dephasing assists the generation of quantum entanglement at distant sites in a chain of electron spins confined in semiconductor quantum dots. One party of an entangled spin pair, prepared at a single site, is transferred to the next site and then adiabatically swapped with a third spin using a transition across a multi-level avoided crossing. This process is accelerated by the noise-induced dephasing through a variant of the quantum Zeno effect, without sacrificing the coherence of the entangled state. Our finding brings insight into the spin dynamics in open quantum systems coupled to noisy environments, opening an avenue to quantum state manipulation utilizing decoherence effects.
description: 33 pages, 5 figures
Novel Printable AlOx Passivation Material and the Process Integration with Commercial Production Line for High Efficiency (20%) PERC Solar Cells
Creators: name: Hung, J.Y.
name: Wang, J.-C.
name: Chen, S.-W.
name: Chen, T.-C.
name: Lin, Y.-S.
name: Ku, C.-H.
name: Wen, C.-C.
Publisher: name: WIP
Year: 2014
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 962-965
description: The candidate of next generation solar cells, PERC-type solar cells, could not be generally mass produced until now partly because of the cost issue and the unpredicted demand of market. For those issues, we developed a new and economic deposition technique for AlOx layer by applying our novel material – “AlOx Passivation Paste” (IP1257) using screen printing which is a standard process/equipment available in all cell manufacturers. As a result, capital investment in high cost deposition equipment could be reduced significantly. Furthermore, after process integration and optimization with in-line production equipment, the average cell efficiency of 20.10 % and Voc of 0.654 V with highest conversion efficiency of more than 20.30 % in one batch of 2,774 standard Mono wafers (156 mm, pseudo square) have been achieved which could be attributed to the excellent rear side passivation quality by the IP1257-AlOx/SiNx stack. Finally, we believe that this technique could become an excellent solution and option for mass production of high efficiency PERC-type solar cells in the near future.
Refinements of the holonomic approximation lemma
Creators: name: Alvarez-Gavela, Daniel
Publisher: name: arXiv
Year: 2016
Subjects: subject: Geometric Topology (math.GT)
subject: Symplectic Geometry (math.SG)
subject: FOS: Mathematics

description: The holonomic approximation lemma of Eliashberg and Mishachev is a powerful tool in the philosophy of the $h-$principle. By carefully keeping track of the quantitative geometry behind the holonomic approximation process, we establish several refinements of this lemma. Gromov's idea from convex integration of working one pure partial derivative at a time is central to the discussion. We give applications of our results to flexible symplectic and contact topology.
description: 30 pages, 18 figures. Comments welcome!
Effect of small floating disks on the propagation of gravity waves
Creators: name: De Santi, Francesca
name: Olla, Piero
Publisher: name: arXiv
Year: 2015
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: FOS: Physical sciences

description: A dispersion relation for gravity waves in water covered by disk-like impurities embedded in a viscous matrix is derived. The macroscopic equations are obtained by ensemble-averaging the fluid equations at the disk scale in the asymptotic limit of long waves and low disk surface fraction. Various regimes are identified depending on the disk radii and the thickness and viscosity of the top layer. Semi-quantitative analysis in the close-packing regime suggests dramatic modification of the dynamics, with orders of magnitude increase in wave damping and wave dispersion. A simplified model working in this regime is proposed. Possible applications to wave propagation in ice-covered ocean is discussed and comparison with field data is provided.
description: 30 pages, 7 figures
Surface Passivation Layers in a-Si:H/ p-Type c-Si Heterojunction Solar Cell
Creators: name: Bobeico, E.
name: Della Noce, M.
name: Lancellotti, L.
name: Mercaldo, L.V.
name: Usatii, I.
name: Izzi, M.
name: Serenelli, L.
name: Tucci, M.
name: Delli Veneri, P.
Publisher: name: WIP
Year: 2014
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 924-927
description: The main goal of amorphous/crystalline silicon heterostructure technology is the very high open circuit
voltage obtainable because of the band bending at the doped amorphous/crystalline silicon (a-Si:H/c-Si) interface and
the use of a thin intrinsic amorphous silicon buffer layer between them. Several limitations still affect the a-Si:H/c-Si
heterostructure based on p-type c-Si wafer, among which the surface defect state density mainly originated by
unsaturated dangling bonds. In this work we analyze the passivation effect of different thin film silicon based
materials, grown by means of PECVD, and its behavior after thermal treatments. Different growth regimes for a-Si:H
films have been used by varying hydrogen dilution (SiH4/H2) and the effective minority carriers lifetime has been
measured by means of quasi-steady-state photoconductance technique. Alternative a-SiOx:H based buffers have been
also considered. Lifetimes above 1 ms have been reached. Intrinsic layer passivation effectiveness has been tested on
silicon heterojunction devices.
Insight from elliptic flow of open charm mesons using quark coalescence model at RHIC and LHC energies
Creators: name: Esha, Roli
name: Nasim, Md.
name: Huang, Huan Zhong
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: A study of elliptic flow of open charm mesons, $D^0$ and $D_S ^\pm$ using quark coalescence as a mechanism of hadronization of heavy quarks implemented in conjunction with A Multi Phase Transport (AMPT) model has been presented. We have studied the transverse momentum dependence of the elliptic flow parameter at mid-rapidity ($|y|$ $
description: 8 pages, 8 figures, Accepted in Journal of Physics G
High Efficient Fully Ion-Implanted, Co-Annealed and Laser-Structured Back Junction Back Contacted Solar Cells
Creators: name: Merkle, A.
name: Peibst, R.
name: Brendel, R.
Publisher: name: WIP
Year: 2014
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 954-958
description: For achieving high energy conversion efficiencies in back junction back contacted (BJBC) solar cells, it is
important to form excellent pn (high-low) junctions between emitter (back surface field (BSF)) and the base while
maintaining high bulk lifetimes, and to apply a rear-side passivation scheme which passivates well both polarities – emitter
and BSF – as well as the pn-junction meander between these regions. The latter aspect is of particular importance for small
BSF indices (i.e., for a large pn-junction meander length), which are required to minimize lateral transport losses of majority
carriers in the Si bulk. In this work, we demonstrate that ion-implanted, co-annealed junctions meet these requirements
when SiO2 – grown in-situ during the annealing process – is utilized as rear-side passivation. For sheet resistances of
130Ω/ (60Ω/) recombination current densities down to 29 fA/cm2 (40 fA/cm²) are achieved for the boron emitter (for
the phosphorus BSF) regions with this passivation scheme. By contrast, Al2O3 yields a slightly better passivation quality
on the boron doped emitter, but the much worse passivation quality of Al2O3 on the phosphorus doped BSF regions and, in
particular, on the pn-junction meander between emitter and BSF, strongly overcompensates this benefit. Therefore, ionimplantation
and co-annealing including in-situ oxide growth does not only strongly reduces process complexity (only one
high temperature step required), but is also preferable regarding the efficiency potential. This is demonstrated on BJBC
cells with average conversion efficiencies >23.5% and a champion efficiency of 24.1% (in-house measurement, designated
area of 3.96cm2). Under reserve of the ongoing independent confirmation, this would correspond to the highest efficiency
reported so far for fully ion-implanted Si solar cells. We achieve these results with an optimized laser structuring that
realizes BSF indices down to 450μm.
Screen-Printable Material and Process Solutions for High-Efficiency Crystalline Silicon Solar Cells
Creators: name: Tanaka, N.
name: Iwamuro, M.
name: Tanaka, T.
name: Kurata, Y.
name: Nojiri, T.
name: Yoshida, M.
name: Sato, E.
Publisher: name: WIP
Year: 2014
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 939-942
description: In this paper, we will describe three kinds of screen-printable materials, that is, n/p-type doping pastes,
surface passivation paste and Cu-alloy electrode paste. The n/p-type doping pastes have three main features: (i)
uniform and controllable sheet resistance, (ii) minimal out-diffusion, and (iii) no residue. These can be applicable to
high-efficiency solar cells such as selective emitter, back contact and bi-facial structure. The surface passivation paste
has also three main features: (i) easy to form thin-layer patterning by screen printing, (ii) field-effect passivation, and
(iii) comparable negative fixed charge density to ALD-Al2O3. Therefore, this can be alternative to ALD or PECVD
passivation for fabricating the local back-surface-field cell in a lower-cost process. The Cu-alloy electrode paste is
the replacement to reduce material cost of the Ag-paste. This paste is composed of Cu-alloy, glass frit, solvent and
binder. By firing at around 800 C, the barrier layer is formed outside of the conductive layer (Cu-alloy) and prevents
Cu-migration to Si. These screen-printable materials enable to provide high-efficiency crystalline silicon solar cell
without significant additional process and cost.
Tricritical points in a compact $U(1)$ lattice gauge theory at strong coupling
Creators: name: De, Asit K.
name: Sarkar, Mugdha
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Pure {\it compact} $U(1)$ lattice gauge theory exhibits a phase transition at gauge coupling $g \sim {\cal{O}}(1)$ separating a familiar weak coupling Coulomb phase, having free massless photons, from a strong coupling phase. However, the phase transition was found to be of first order, ruling out any nontrivial theory resulting from a continuum limit from the strong coupling side. In this work, a compact $U(1)$ lattice gauge theory is studied with addition of a dimension-two mass counterterm and a higher derivative (HD) term that ensures a unique vacuum and produces a covariant gauge-fixing term in the naive continuum limit. For a reasonably large coefficient of the HD term, now there exists a continuous transition from a regular ordered phase to a spatially modulated ordered phase. For weak gauge couplings, a continuum limit from the regular ordered phase results in a familiar theory consisting of free massless photons. For strong gauge couplings with $g\ge {\cal{O}}(1)$, this transition changes from first order to continuous as the coefficient of the HD term is increased, resulting in tricritical points which appear to be a candidate in this theory for a possible nontrivial continuum limit.
description: 6 pages, 6 figures, narrative part of the paper enlarged, version published in journal
micompr: An R Package for Multivariate Independent Comparison of Observations
Creators: name: Fachada, Nuno
name: Rodrigues, João
name: Lopes, Vitor V.
name: Martins, Rui C.
name: Rosa, Agostinho C.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mathematical Software (cs.MS)
subject: Computation (stat.CO)
subject: FOS: Computer and information sciences
subject: G.3
subject: 62-07, 62H15, 62H25

description: The R package micompr implements a procedure for assessing if two or more multivariate samples are drawn from the same distribution. The procedure uses principal component analysis to convert multivariate observations into a set of linearly uncorrelated statistical measures, which are then compared using a number of statistical methods. This technique is independent of the distributional properties of samples and automatically selects features that best explain their differences. The procedure is appropriate for comparing samples of time series, images, spectrometric measures or similar high-dimension multivariate observations.
description: The peer-reviewed version of this paper is published in The R Journal at https://journal.r-project.org/archive/2016-2/fachada-rodrigues-lopes-etal.pdf . This version is typeset by the authors and differs only in pagination and typographical detail
Deep Diffusion of Phosphorous in Silicon Using 1070 nm Laser
Creators: name: Mondal, S.
name: Singh Solanki, C.
Publisher: name: WIP
Year: 2014
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 29th European Photovoltaic Solar Energy Conference and Exhibition; 911-914
description: Laser doping of phosphorous in silicon using 1070 nm fiber laser has been studied in this work. The
primary objective is to study the depth of diffusion which is characterized by the p-n junction depth. Deep diffusion is
useful for carrier collection from bulk region in low lifetime substrates. The surface morphology after laser doping
suggests multiple heating-cooling cycles of the surface and subsurface region. Spin-on-dopant layer has been used as
the source of phosphorous atoms for laser doping. Sheet resistance as low as 1.5 / has been obtained. Such low
sheet resistance suggests formation of deep junction as well as high doping concentration near the surface. The
retention time of laser has been varied by changing the scan speed of the laser and its effect on sheet resistance has
been observed. Variation of sheet resistance and junction depth with pulse length is also presented. Junction depth
measurement has been done using electron beam induced current (EBIC) and glow discharge mass spectrometry
(GDMS). Junction depth value of 14 μm has been obtained.