Miracle-dz/UniFAR-FTUs huggingface dataset:
Measurement of the Knight field and local nuclear dipole-dipole field in an InGaAs/GaAs quantum dot ensemble

We present a comprehensive investigation of the electron-nuclear system of negatively charged InGaAs/GaAs self-assembled quantum dots (QDs) under the influence of weak external magnetic fields (up to 3 mT). We demonstrate that, in contrast to conventional semiconductor systems, these small fields have a profound influence on the electron spin dynamics, via the hyperfine interaction. QDs, with their comparatively limited number of nuclei, present electron-nuclear behavior that is unique to low-dimensional systems. We show that the conventional Hanle effect used to measure electron-spin relaxation times, for example, cannot be used in these systems when the spin lifetimes are long. An individual nucleus in the QD is subject to milli-Tesla effective fields, arising from the interaction with its nearest neighbors and with the electronic Knight field. The alignment of each nucleus is influenced by application of external fields of the same magnitude. A polarized nuclear system, which may have an effective field strength of several Tesla, may easily be influenced by these milli-Tesla fields. This in turn has a dramatic effect on the electron-spin dynamics and we use this technique to gain a measure of both the dipole-dipole field and the maximum Knight field in our system thus allowing us to estimate the maximum Overhauser field that may be generated at zero external magnetic field. We also show that one may fine tune the angle which the Overhauser field makes with the optical axis.
Equilibration and thermalization in finite quantum systems

Experiments with trapped atomic gases have opened novel possibilities for studying the evolution of nonequilibrium finite quantum systems, which revived the necessity of reconsidering and developing the theory of such processes. This review analyzes the basic approaches to describing the phenomena of equilibration, thermalization, and decoherence in finite quantum systems. Isolated, nonisolated, and quasi-isolated quantum systems are considered. The relations between equilibration, decoherence, and the existence of time arrow are emphasized. The possibility for the occurrence of rare events, preventing complete equilibration, are mentioned.
A BROADBAND STUDY OF THE EMISSION FROM THE COMPOSITE SUPERNOVA REMNANT MSH 11–62

MSH 11–62 (G291.0–0.1) is a composite supernova remnant for which radio and X-ray observations have identified the remnant shell as well as its central pulsar wind nebula. The observations suggest a relatively young system expanding into a low-density region. Here, we present a study of MSH 11–62 using observations with the Chandra, XMM-Newton, and Fermi observatories, along with radio observations from the Australia Telescope Compact Array. We identify a compact X-ray source that appears to be the putative pulsar that powers the nebula, and show that the X-ray spectrum of the nebula bears the signature of synchrotron losses as particles diffuse into the outer nebula. Using data from the Fermi Large Area Telescope, we identify γ-ray emission originating from MSH 11–62. With density constraints from the new X-ray measurements of the remnant, we model the evolution of the composite system in order to constrain the properties of the underlying pulsar and the origin of the γ-ray emission.
Convolutional neural network-based optimal R-λ intra rate control in Versatile Video Coding

Abstract. Since intra frame rate control has no prior information to rely on, it is difficult to obtain suitable initial rate control parameters for achieving optimal intra coding. The optimal bit allocation and λ decision are proposed based on a convolutional neural network (CNN) in R-λ intra frame rate control. First, according to the rate distortion (R-D) and rate lambda (R-λ) relationships of the coding tree unit (CTU), a CNN with four outputs is designed to predict the key parameters of R-D and R-λ curves. Second, with the R-D optimization of a frame, the coding optimization equation of the frame λ and the target bit can be built to derive the optimal CTU bit allocation. Last, a suitable CTU λ can be obtained based on the allocated bit and predicted R-λ curve for a CTU to minimize the total distortion of the current frame. The experimental results show that the proposed algorithm can improve the intra frame rate control performance by 0.31 dB with a good rate control accuracy of 4.76%.
An Online Condition Monitoring Method for Series-Connected IGBTs to Avoid Cascading Failure

The series-connected insulated gate bipolar transistors (IGBTs) have numerous applications in industry and research fields. One of the risks of the resultant series high-voltage switch (RSHVS) is the IGBTs short-circuit failure. The number of the IGBTs in an RSHVS is usually designed with an appropriate voltage derating factor to make it resilient against a limited number of the IGBTs short-circuit failures. However, by the increased number of failures, the withstand voltage of the healthy IGBTs finally violates the IGBTs’ tolerable voltage in the off-state. In such conditions, a cascading failure occurs and breaks all remaining healthy IGBTs. In this article, we propose a condition monitoring (CM) method to avoid cascading failure in RSHVSs. The proposed method works based on the change of the rising edge of the load current in the RSHVS turning-on time. It will be shown that, when some of the IGBTs in the series structure fail short, the turning-on time of the RSHVS increases. Thus, the rising edge of the current also increases that leads to the decrement of high-order harmonics magnitude. The proposed CM analyzes such harmonics and provides a constant voltage as the CM output. The performance of the proposed CM is evaluated using simulations and experiments for an RSHVS consisting of eight IGBTs.
PIC Simulations of Velocity-space Instabilities in a Decreasing Magnetic Field: Viscosity and Thermal Conduction

We use particle-in-cell (PIC) simulations of a collisionless, electron–ion plasma with a decreasing background magnetic field, , to study the effect of velocity-space instabilities on the viscous heating and thermal conduction of the plasma. If decreases, the adiabatic invariance of the magnetic moment gives rise to pressure anisotropies with ( and represent the pressure of species j (electron or ion) parallel and perpendicular to B). Linear theory indicates that, for sufficiently large anisotropies, different velocity-space instabilities can be triggered. These instabilities in principle have the ability to pitch-angle scatter the particles, limiting the growth of the anisotropies. Our simulations focus on the nonlinear, saturated regime of the instabilities. This is done through the permanent decrease of by an imposed plasma shear. We show that, in the regime ( ), the saturated ion and electron pressure anisotropies are controlled by the combined effect of the oblique ion firehose and the fast magnetosonic/whistler instabilities. These instabilities grow preferentially on the scale of the ion Larmor radius, and make (where ). We also quantify the thermal conduction of the plasma by directly calculating the mean free path of electrons, , along the mean magnetic field, finding that depends strongly on whether decreases or increases. Our results can be applied in studies of low-collisionality plasmas such as the solar wind, the intracluster medium, and some accretion disks around black holes.
Entanglement temperature and perturbed AdS 3 geometry

In analogy to the first law of thermodynamics, the increase in entanglement entropy $\delta S$ of a conformal field theory (CFT) is proportional to the increase in energy, $\delta E$, of the subsystem divided by an effective entanglement temperature, $T_E$. Extending this analogy, we study entanglement entropy when the subsystem is perturbed by applying an external field, expressed as a coupling to a local marginal operator in the CFT. We show that the resulting entropy change is associated with a change in the entanglement temperature itself, leading to an equation analogous to the Clausius relation. Using AdS/CFT duality we develop a relationship between a perturbation in the local entanglement temperature, $\delta T_E(x)$ of the CFT and the perturbation of the bulk AdS metric. Using the AdS$_3$ minimal surface as a probe, we can construct bulk metric perturbations from an exact numerical computation of the entanglement temperature in a two dimensional $c=1$ boundary theory deformed by a marginal perturbation.
Obtaining mass parameters of compact objects from redshifts and blueshifts emitted by geodesic particles around them

The mass parameters of compact objects such as Boson Stars, Schwarzschild, Reissner Nordstrom and Kerr black holes are computed in terms of the measurable redshift-blueshift (zred, zblue) of photons emitted by particles moving along circular geodesics around these objects and the radius of their orbits. We found bounds for the values of (zred, zblue) that may be observed. For the case of Kerr black hole, recent observational estimates of SrgA\* mass and rotation parameter are employed to determine the corresponding values of these red-blue shifts.
Anomalous molecular dynamics in the vicinity of a conical intersection

Conical intersections between molecular electronic potential energy surfaces can greatly affect molecular dynamics and chemical properties. Molecular gauge theory is capable of explaining many of these often unexpected phenomena deriving from the physics of the conical intersection. Here we will give an example of anomalous dynamics in the paradigm E × ϵ Jahn-Teller model, which does not allow for a simple explanation in terms of standard molecular gauge theory. By introducing a dual gauge theory, we unwind this surprising behavior by identifying it with an intrinsic spin Hall effect. Thus, this work link knowledge of condensed-matter theories with non-adiabatic molecular dynamics. Furthermore, via ab initio calculations of potential energy surfaces, the findings are as well demonstrated to appear in a realistic system such as the Li3 molecule.
Dopant-enhanced solid-phase epitaxy in buried amorphous silicon layers

The kinetics of intrinsic and dopant-enhanced solid-phase epitaxy (SPE) is studied in buried amorphous Si layers in which SPE is not retarded by H. As, P, B, and Al profiles were formed by multiple energy ion implantation over a concentration range of $(1\char21{}30)\ifmmode\times\else\texttimes\fi{}{10}^{19}∕{\mathrm{cm}}^{3}$. Samples were annealed in air at temperatures in the range $460\char21{}660\phantom{\rule{0.2em}{0ex}}\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$ and the rate of interface motion was monitored using time-resolved reflectivity. The dopant-enhanced SPE rates were modeled with the generalized Fermi level shifting model using degenerate semiconductor statistics. The effect of band bending between the crystalline and amorphous sides of the interface is also considered.
Active galactic nuclei-driven outflows without immediate quenching in simulations of high-redshift disc galaxies

We study outflows driven by Active Galactic Nuclei (AGNs) using high- resolution simulations of idealized z=2 isolated disk galaxies. Episodic accretion events lead to outflows with velocities >1000 km/s and mass outflow rates up to the star formation rate (several tens of Msun/yr). Outflowing winds escape perpendicular to the disk with wide opening angles, and are typically asymmetric (i.e. unipolar) because dense gas above or below the AGN in the resolved disk inhibits outflow. Owing to rapid variability in the accretion rates, outflowing gas may be detectable even when the AGN is effectively "off. " The highest velocity outflows are sometimes, but not always, concentrated within 2-3 kpc of the galactic center during the peak accretion. With our purely thermal AGN feedback model -- standard in previous literature -- the outflowing material is mostly hot (10^6 K) and diffuse (nH Gyr) timescales.
Scattering and Pairing in Cuprate Superconductors

The origin of the exceptionally strong superconductivity of cuprates remains a subject of debate after more than two decades of investigation. Here we follow a new lead: The onset temperature for superconductivity scales with the strength of the anomalous normal-state scattering that makes the resistivity linear in temperature. The same correlation between linear resistivity and Tc is found in organic superconductors, for which pairing is known to come from fluctuations of a nearby antiferromagnetic phase, and in pnictide superconductors, for which an antiferromagnetic scenario is also likely. In the cuprates, the question is whether the pseudogap phase plays the corresponding role, with its fluctuations responsible for pairing and scattering. We review recent studies that shed light on this phase—its boundary, its quantum critical point, and its broken symmetries. The emerging picture is that of a phase with spin-density-wave order and fluctuations, in broad analogy with organic, pnictide, and heavy-fermion superconductors.
A SYSTEMATIC SEARCH FOR MASSIVE BLACK HOLE BINARIES IN THE SLOAN DIGITAL SKY SURVEY SPECTROSCOPIC SAMPLE

We present the results of a systematic search for massive black hole binaries in the Sloan Digital Sky Survey (SDSS) spectroscopic database. We focus on bound binaries, under the assumption that one of the black holes is active. In this framework, the broad lines associated with the accreting black hole are expected to show systematic velocity shifts with respect to the narrow lines, which trace the rest frame of the galaxy. For a sample of 54,586 quasars and 3929 galaxies at redshifts 0.1 < z < 1.5, we brute-force model each spectrum as a mixture of two quasars at two different redshifts. The spectral model is a data-driven dimensionality reduction of the SDSS quasar spectra based on a matrix factorization. We identified 32 objects with peculiar spectra. Nine of them can be interpreted as black hole binaries. This doubles the number of known black hole binary candidates. We also report on the discovery of a new class of extreme double-peaked emitters with exceptionally broad and faint Balmer lines. For all the interesting sources, we present detailed analysis of the spectra and discuss possible interpretations.
A Case Report of a Sacral Giant Cell Tumor Treated With Block Resection and Lumbo-Pelvic Fixation

Giant cell tumors (GCT) are benign but locally aggressive neoplasms composed of osteoclast-like giant cells and fusiform to ovoid mononuclear stromal cells. GCT generally comprise 5-10% of all benign bone tumors; they appear most frequently between the second and third decades of life. These tumors are also distributed throughout the vertebral column. Approximately half of all spinal GTCs develop in the sacrum. Many cases remain clinically silent and are discovered incidentally during the study of minor trauma. Symptomatic tumors often mimic other common spinal pathologies. Imaging studies ideal for diagnosis are CT and MRI. The techniques used in the treatment of giant cell tumors are curettage or intralesional surgery, block resection, radiotherapy, and chemotherapy. Herein, we report on a 23-year-old female patient diagnosed with a tumoral mass in the anterior part of the sacrum, suggestive of GCT. The lesion was completely excised in two consecutive surgeries, and lumbopelvic fixation was performed with favorable immediate postoperative results. Careful surgical planning with a multi-disciplinary approach leading to block resection still remains the most viable option for the treatment of vertebral GCT.
An Attentional Extractive Summarization Framework

Although currently, works on text summarization generally use abstractive approaches, extractive methods can be specially adequate for some applications, and they can help with other tasks such as Question Answering or Information Extraction. In this paper, we propose a general framework for extractive summarization, the Attentional Extractive Summarization framework. The proposed approach is based on the interpretation of the attention mechanisms of hierarchical neural networks, that compute document-level representations of documents and summaries from sentence-level representations, which, in turn, are computed from word-level representations. The models proposed under this framework are able to automatically learn relationships among document and summary sentences, without requiring oracle systems to compute reference labels for each sentence before the training phase. We evaluate two different systems, formalized under the proposed framework, on the CNN/DailyMail and the NewsRoom corpora, which are some of the reference corpora in the most relevant works in text summarization. The results obtained during the evaluation support the adequacy of our proposal and they suggest that there is still room for the improvement of our attentional framework.
HOW THE DENSITY ENVIRONMENT CHANGES THE INFLUENCE OF THE DARK MATTER–BARYON STREAMING VELOCITY ON COSMOLOGICAL STRUCTURE FORMATION

We study the dynamical effect of the relative velocity between dark matter and baryonic fluids, which remained supersonic after the epoch of recombination. The impact of this supersonic motion on the formation of cosmological structures was first formulated by Tseliakhovich & Hirata, in terms of the linear theory of small-scale fluctuations coupled to large-scale, relative velocities in mean-density regions. In their formalism, they limited the large-scale density environment to be that of the global mean density. We improve on their formulation by allowing variation in the density environment as well as the relative velocities. This leads to a new type of coupling between large-scale and small-scale modes. We find that the small-scale fluctuation grows in a biased way: faster in the overdense environment and slower in the underdense environment. We also find that the net effect on the global power spectrum of the density fluctuation is to boost its overall amplitude from the prediction by Tseliakhovich & Hirata. Correspondingly, the conditional mass function of cosmological halos and the halo bias parameter are both affected in a similar way. The discrepancy between our prediction and that of Tseliakhovich & Hirata is significant, and therefore, the related cosmology and high-redshift astrophysics should be revisited. The mathematical formalism of this study can be used for generating cosmological initial conditions of small-scale perturbations in generic, overdense (underdense) background patches.
Determination of a magnetization parameter of the parsec-scale AGN jets

The observed shift of the core of the relativistic AGN jets as a function of frequency allows us to evaluate the number density of outflowing plasma and, hence, the magnetization parameter. New analysis of more than 20 sources shows that for most of jets the magnetization parameter ~ 10 - 100. Since the magnetization parameter is the maximum possible bulk Lorentz-factor of the relativistic flow, this estimate is consistent with the observed superluminal motion.
Comment on AMS02 results support the secondary origin of cosmic ray positrons

We present a simple calculation of the flux of secondary positrons produced in the ISM that is based only on priors. Our calculated ISM flux agrees very well with that calculated with the elaborate GALPROP code. It confirms that secondary production of positrons in the ISM by the primary cosmic rays cannot explain the observed sub-TeV flux of CR positrons. Moreover, we show that once energy loss of positrons in source and in the ISM are included, secondary production inside the CR sources plus the ISM does explain the measured near-Earth flux of cosmic ray positrons.
You Lie, I Leave: Dynamic Cheap Talk under Receiver Commitment

When can naive agents influence the recommendations of an expert? Consider a dynamic cheap talk game where receivers directly accept recommendations from a privately informed sender. Generically, senders can secure their maximal payoff by directly recommending their most preferred action. However, when receivers can commit to ignore future messages, they can link senders’ incentives across time to induce truthful revelation. I formalize this intuition, explicitly construct an equilibrium, and show all equilibria are behaviorally equivalent. When payoffs are concave supermodular , every equilibrium is summarized by a cutoff statistic: misrepresentation occurs only if the state is sufficiently high. If states are intertemporally correlated, equilibrium are ranked: more informative correlation structures decrease truthfulness. Should senders have reputational concerns, commitment leads to state-contingent interval pooling of types, encouraging truthfulness. Finally, I apply these insights to discuss optimal enforcement of perjury law and communication by a (po-tentially) corrupt government.
Preparation of light-atom tips for scanning probe microscopy by explosive delamination

To obtain maximal resolution in scanning tunneling microscopy (STM) and atomic force microscopy, the size of the protruding tip orbital has to be minimized. Beryllium as tip material is a promising candidate for enhanced resolution because a beryllium atom has just four electrons, leading to a small covalent radius of only 96 pm. Besides that, beryllium is conductive and has a high elastic modulus, which is a necessity for a stable tip apex. However, beryllium tips that are prepared ex situ are covered with a robust oxide layer, which cannot be removed by just heating the tip. Here, the authors present a successful preparation method that combines the heating of the tip by field emission and a mild collision with a clean metal plate. That method yields a clean, oxide-free tip surface as proven by a work function of Φexpt=5.5 eV as deduced from a current-distance curve. Additionally, a STM image of the Si-(111)-(7×7) is presented to prove the single-atom termination of the beryllium tip.
gamma-hadron correlations as a tool to trace the flow of energy lost from hard partons in heavy-ion collisions

High transverse momentum (${P}_{T}$) $\ensuremath{\gamma}$-hadron correlations are currently being regarded as the ``golden channel'' for the study of the medium produced in ultrarelativistic heavy-ion collisions by means of hard probes. This is for several reasons, all linked to the fact that because of the smallness of the electromagnetic coupling $\ensuremath{\alpha}$, the photon does not substantially interact with the medium and is expected to escape unmodified. Thus, a high ${P}_{T}$ photon indicates a hard process in the collision independent of the position of the hard vertex. In contrast, there may not be a clear signal for a hard process involving strongly interacting partons if the production vertex is deep in the medium as both partons undergo substantial final state interaction. Equally important, if photon production by fragmentation can be separated experimentally, the photon provides almost full knowledge of the initial kinematics. In the present paper, these properties are used to demonstrate a distinguishing feature between two assumptions made in modeling the medium modifications of strongly interacting high ${P}_{T}$ processes: loss of energy into the medium vs medium modification of the partonic shower. It is shown that $\ensuremath{\gamma}$-hadron correlations provide a very clean signature for distinguishing the two scenarios.
Entanglement renormalization, scale invariance, and quantum criticality

The use of entanglement renormalization in the presence of scale invariance is investigated. We explain how to compute an accurate approximation of the critical ground state of a lattice model and how to evaluate local observables, correlators, and critical exponents. Our results unveil a precise connection between the multiscale entanglement renormalization ansatz and conformal field theory (CFT). Given a critical Hamiltonian on the lattice, this connection can be exploited to extract most of the conformal data of the CFT that describes the model in the continuum limit.