bluuebunny/crossref_metadata_2025 huggingface dataset:
Electron density variation in a YBa2Cu3O7 crystal upon replacement of Ba2+ by a rare-earth ion (R3+)
Authors: Voloshin V. A. , Babenko V. V. , But’ko V. G. , Reznik I. M. , Yuzhelevskii Ya. I.
Published: January 2025

The electron density of four unit cells in the system RBaCuO is calculated and maps of its distribution constructed. In one of the unit cells, Ba2+ is replaced by R3+. It is shown that this substitution strongly deforms the distribution of electron density near the Ba2+ site, thus leading to the formation of covalent bonds between the rare-earth ion and the nearest oxygen ions. It is assumed that these processes affect the mechanism of suppression of superconductivity.
Superconductivity in (Hg0.83Cu0.17)Ba2CuO4+δ at a temperature above 120 K
Authors: Lutsiv R. V. , Aksel’rud L. G. , Myasoedov Yu. N. , Matviiv M. V. , Kityk I. V.
Published: January 2025

The superconducting compound (Hg0.83Cu0.17)Ba2CuO4+δ is obtained by the method of solid-phase synthesis with the beginning of the transition from the paramagnetic to the diamagnetic state at a temperature of 125 K. The coordinates of the atoms, the isotropic thermal parameters and the interatomic distances were made more precise by x-ray structure analysis. In the compound (Hg0.83Cu0.17)Ba2CuO4.05 the appearance of optical generation of the second harmonic (GSH) of a YAG laser (λ =1.05 μm) was first observed at 130 K. This indicates the appearance of an acentric distribution of the electron density, which correlates with the appearance of the superconducting phase transition. It is proposed that the increase in Tc is associated with the formation of two layers [CuO2] in the average elementary cell in the case of replacement of some of the atoms of Hg by Cu and by the partial filling of the 2(f) positions by oxygen atoms.
Nucleation and phase separation in superfluid solutions of 3He–4He upon a change in concentration
Authors: Mikheev V. A. , Rudavskii E. Ya. , Chagovets V. K. , Sheshin G. A.
Published: January 2025

Simultaneous measurements of the first sound velocity and dielectric constant at 90 mK are used to study the probability of phase separation of superfluid 3He−4He solutions and the dependence of supersaturation on the rate of increase in the solution concentration. It is found that the latter has the form of a weak power dependence. The obtained results allow us to compare and analyze all the available experimental data on the supersaturation of 3He−4He solutions.
Lattice parameters and thermal expansion of solid paradeuterium
Authors: Prokhvatilov A. I. , Strzhemechnyi M. A. , Shcherbakov G. N.
Published: January 2025

Systematic data are obtained for the first time on the lattice parameters, molar volume, density, and the x-ray thermal expansion coefficients of the high-temperature hcp phase of p-D2 (xJ = 1 = 0.86) in the temperature interval 4.5–18.5 K. Quantitative characteristics of the effect of the quadrupole subsystem on structural (parameters and lattice volume) and thermodynamic (thermal expansion and Gruneisen’s constant) properties of deuterium are obtained from a comparison with the results of previous investigations of orthodeuterium (xJ = 1 = 0.025). It is shown that the effect is the strongest at low temperatures when the contribution from the rotational subsystem dominates.
Density of states peculiarities of anisotropic superconductors in the strong-coupling limit
Authors: D’yachenko A. I.
Published: January 2025

The numerical solution of the Eliashberg equations is used to demonstrate that a universal blurring mechanism of gap singularities existing in the density of states N(ω) of anisotropic conductors in the limit of large electron-phonon interaction constants λ > 3–4 is effective even at a temperature T → 0. For this reason, the observation of sharp BCS-like singularities in N(ω) of cuprates makes it impossible to explain high-temperature superconductivity by using the Eliashberg theory with λ ⩾ 3.
Current distribution and degradation of superconductivity in large contacts containing a type II superconductor
Authors: Lysykh A. A. , Zasetskii G. V. , Bagatskii V. M. , Yanson I. K.
Published: January 2025

Phenomena associated with electron transport in normal metal-type II superconductor contacts of diameter 1–70 μm are studied. The superconductivity is destroyed as the current density attains the critical value for which the vortex motion becomes continuous. Contrary to the earlier assumptions, the voltage Vc1 is not directly connected with the energy gap of the superconductor, but is rather determined by the normal electrode and depends on the ratio of the electron mean free path Ii in the normal metal and the contact diameter d. Various current distributions may be realized in point contacts. For relatively clean contacts made of normal metals (Ii = d), as well as clean contacts with a thin (t ≪ d) damaged layer at the boundary between electrodes, the current density is constant over the sample cross-section. In extremely “dirty” contacts (Ii ≪ d), annular current flow is realized, the current density being low at the center and increasing towards the contact periphery. In the absence of an external magnetic field, the current in S–c–S contacts also flows in a ring whose diameter begins to increase as the field generated by the current exceeds Hc1 and the vortices penetrate the contact cross-section.
Surface impedance of epitaxial HTS films in the mixed state
Authors: Melkov G. A. , Kasatkin A. L. , Malyshev V. Yu.
Published: January 2025

Surface impedance of epitaxial films is studied as a function of a external magnetic field. The experimentally obtained values of the pinning constant are about an order of magnitude higher than the values obtained from the critical current of the film. The variation of the microwave properties of epitaxial HTS films in a constant magnetic field is anomalously small: at helium temperatures, the surface resistance variation does not exceed 3% in a magnetic field of 4 kOe for 1–2–3 films deposited on sapphire. The temperature dependence of the surface resistance of HTS films in the mixed state had a peak near the vortex lattice unpinning temperature. In weak constant magnetic fields (up to 102 Oe), the surface resistance increases due to intergranular defects.
Magnetic relaxation of 57Fe nuclei in magnetoplumbite
Authors: Bezlepkin A. A. , Iraki M. R. , Kuntsevich S. P. , Palekhin V. P.
Published: January 2025

Peculiarities of spin-spin and spin-lattice relaxation rate of 57Fe nuclei in magnetoplumbite are studied experimentally in the interval 4.2–295 K. Peaks have been observed for the spin-spin and spin-lattice relaxation rates in the temperature interval 4.2–77 K for all crystallographically nonequivalent positions of iron ions. The temperature dependence of the FMR line width has been studied for the same samples in which FMR was studied. A peak on this dependence was observed at 170 K at a frequency of 53.9 GHz. Peculiarities in the relaxation of nuclear and electron spins observed in lead hexaferrite are associated with the presence of Fe2+ impurity ions and are explained by the theory of slow relaxation associated with the Fe2+⇆ Fe3+ valency exchanges. The activation energy E = 2.5·10−2 eV for the valency exchange process and the relaxation time τ∞ = 0.53 ps are obtained from a combined analysis of FMR and NMR data. It is shown that the nuclear spin-spin relaxation rate at domain boundaries is much higher than in the domains.
Modulated antiferromagnetic structure on a plane triangular lattice
Authors: Lavrinenko N. M.
Published: January 2025

It is well known that the ground state of a modulated magnetic structure has a specific continuous degeneracy associated with the uncertainty in the phase of the noncommensurate structure. On the other hand, the existence of continuous degeneracy in a two-dimensional spin system may lead, according to the Mermin-Wagner theory, to a violation of the long-range orientational order and thus cast a doubt on the very possibility of the existence of noncommensurate magnetic structures in two-dimensional systems. Such a situation is analyzed in the present work by considering the example of a modulated antiferromagnetic structure in a plane hexagonal lattice. It is shown that in this case the long-range orientational order is indeed broken by fluctuations. However, the magnetic symmetry is found to be lower than the symmetry of the actual paraphase but higher than the symmetry of the orientationally ordered magnetic state. The method of quasiaverages is used to propose a microscopic description of the statistical equilibrium state of the spin system, and the equations of motion are derived.
Kinetics of phase transition to superconductivity. Vortices as a long way to equilibrium
Authors: Filippov A. E. , Radievskii A. V. , Zel’tser A. S.
Published: January 2025

The kinetics of fluctuational formation of vortex pairs in a superconductor upon a transition from a paraphase to the ordered state is studied. It is shown in the framework of the numerical experiments that such pairs are stably generated by typical configurations of a two-component order parameter as it interacts with the electromagnetic gauge field. The role of these excitations in inducing a first-order phase transition to superconductivity is discussed.
Domain walls connected with spontaneous deformation of an antiferromagnetic chain
Authors: Kosevich A. M.
Published: January 2025

A 1D model of an antiferromagnet (AFM) is analyzed, in which the Frenkel-Kontorova model is generalized to the system of two fields: the atomic displacement field and the field of atomic spin orientations. It is assumed that the equilibrium ordering of atomic masses associated with mechanical interactions between atoms corresponds to a completely frustrated spin ordering. However, magnetoelastic interaction generates a spontaneous uniform deformation leading to either a doubly degenerate, or nondegenerate ground state of the AFM. In both cases, magnetic domains separated by a domain wall (DW) (which is the soliton solution of the nonlinear equation for the displacement field) can be formed. It is shown that DW can be of two types. A domain wall of the first type preserves the uniformity of spin distribution in a chain and is determined only by the type of kink (large or small) in the displacement field. Such a DW includes either a vacancy, or a crowdion, viz., inelastic deformation of the displacement field. A domain wall of the second type is a 2π-kink in the spin orientation field and causes deformation of the displacement field without violating the atomic ordering in the chain.
Anomalous phonon drag in point contacts in a magnetic field
Authors: Shkorbatov A. G.
Published: January 2025

It is shown that the phonon drag and the asymmetry in heat release in metallic point contacts (PC) introduced in a strong magnetic field are very sensitive to the ratio of PC apertures for phonons and electrons. A distinguishing feature of the proposed mathematical model of PC is that the diameter d of the PC aperture for electrons is assumed to be much smaller than the diameter D of the aperture for phonons. In this case, the application of a magnetic field to a PC may considerably increase the phonon drag thermoemf in the PC (by a factor of D/d2).
Equilibrium and stability of vortex chains in superfluid helium in rotating rings of arbitrary size
Authors: Tyuptsov A. D. , Zueva T. I.
Published: January 2025

In this work, we consider the flow of He II between two concentric cylinders rotating with the same angular velocity. By representing the velocity of the superfluid component in terms of Weierstrass’ ζ-function, an expression is derived for the free energy of a rotating superfluid liquid with vortices in rings of arbitrary size. The obtained condition for the energy minimum indicates that in the equilibrium state, the vortices are situated at a point in the liquid where the velocity generated by them is the same as that of the normal component. An algorithm has been worked out to determine the moment of emergence and the position of any number of vortices. Some results of numerical experiments are presented, including the position of the first vortex and the instant of its emergence, free energy for different values of parameters, and the angular velocity for which the emergence of N vortices becomes advantageous from the energy point of view for some specific values of N.
Thermodynamics and equations of motion for quantum spin crystals
Authors: Isaev A. A. , Kovalevskii M. Yu.
Published: January 2025

Hamiltons’s approach is used for obtaining nonlinear dynamic equations for a quantum spin crystal. The second law of thermodynamics is formulated. Expressions for flux densities of additive integrals of motion are derived in terms of thermodynamic potential density both for Galilean-invariant and Galilean-noninvariant systems. Time-independent solutions corresponding to helical magnetic ordering are obtained. The nonuniformity of the magnetic field is taken into account in dynamics equations.
Hall currents in a 2D electron system with a nearly integral filling factor
Authors: Shikin V. B.
Published: January 2025

A modification of MacDonald’s theory [A. H. MacDonald et al., Phys. Rev. B 28, 3648 (1983)] on distribution of Hall currents in 2D electron systems with a filling factor ν close to an integer is proposed. The computational algorithm contains the diagonal current component introduced phenomenologically and takes into account the coordinate dependence of the electrochemical potential μ. It is shown that the relation eφ ≈ μ, where φ is the electric potential, is fulfilled under certain conditions existing over a wide range of temperature and sample dimensions. Both potentials (μ and φ) in this case are harmonic functions of the coordinates. The harmonic approximation introduced in this way is used for solving several typical problems demonstrating the role of “bulk” component of Hall currents. This concerns above all the general pattern of distribution of Hall currents, taking into account their introduction into the sample and extraction from it, the so-called compensation effect, and so on. It is found that the predictions of harmonic approximation are in accord with Buttiker’s approximation, but differ from it in the description of the local characteristics of a Hall-type sample. A new technique is proposed for a contactless observation of the Hall current and electric field distributions under conditions close to an integral filling of Landau levels.
Helical waves in metals with magnetoimpurity electron states
Authors: Gleizer N. V. , Ermolaev A. M. , Rashba G. I.
Published: January 2025

Helical electromagnetic waves in the electron-hole plasma of normal noncompensated metals with magnetoimpurity electron states are considered. It is found that the rearrangement of the spectrum of the waves in the vicinity of resonance transitions of electrons between Landau levels and magnetoimpurity levels is accompanied by the emergence of new branches. The spectrum and damping decrement of the waves are calculated in the vicinity of resonance frequencies. The electromagnetic field distribution in the bulk of the metal is determined. The surface impedance of the metal half-space with magnetoimpurity states is calculated. Resonances of impedance at limiting frequencies are observed in the spectrum of helical waves.
Inelastic interaction of low-energy mass-selected ions with a surface of solid xenon
Authors: Kolmakov A. A. , Stankevich V. V.
Published: January 2025

The processes of charge exchange in impingent ions and the formation of electron excitations in inert gas matrices are studied experimentally by considering the example of Xe films bombarded by slow Ne+ and Xe+ ions (Ekin<10 eV) as well as alkali metal ions. It is shown that, at such collision energies, we can neglect the effects of kinetically stimulated charge exchange and matrix excitation. However, these effects must be taken into consideration for Ekin>100 eV. For the ion-surface combinations considered by us, the main channels of charge exchange for slow collisions are the Auger processes and the quasiresonance neutralization. A model is proposed for describing these effects.
On the shape of EPR line in magnetodilute crystals
Authors: Buishvili L. L. , Kobakhidze G. V.
Published: January 2025

The shape of the absorption line in magnetodilute samples at low temperatures is analyzed by the memory function method. It is shown that, in contrast to the approximation of the cut-off Lorentzian shape of the line, the memory function method gives the Gaussian decrease in absorption for a detuning above the cut-off parameter.
Influence of the external N and P inputs on nutrients in the coastal area of Xiamen, China
Authors: Dai Siying , Hu Jiehua , Wang Shanshan , Huang Siming , Tian Rong , Zhao Shuhui , Luo Yang , Zhang Xiaoke , Sun Xia , Yan Jinpei
Published: January 2025

Environmental context External nutrients giving rise to critical ecological issues of the coastal seawater. We investigated the nearshore nutrient concentrations and their sources in Xiamen Bay during 2013–18. Our results could provide theoretical support for controlling nearshore nutrient pollution. Rationale External nutrients greatly increase the critical ecological risks of the coastal seawater. Therefore, it is important to understand the sources and variation characteristics of nitrogen (N) and phosphorus (P) in the coastal area. Methodology The dissolved inorganic nitrogen (DIN) and phosphate (PO4–P) in coastal Xiamen were monitored from 2013 to 2018. The input of nitrogen from runoff in the coastal Xiamen was calculated from the runoff flow amount collected by Xiamen Marine and Fisheries Bureau. Atmospheric dry deposition of DIN was simulated using Williams model to analyse the potential sources of nutrients in the coastal Xiamen. Results High DIN and PO4–P levels occurred in the inner bay and decreased dramatically outside Xiamen Bay. The lowest values of DIN and PO4–P were observed in summer, which is consistent with the temporal variation in nutrient inputs from the surface runoff and atmospheric deposition. The nutrient input of Jiulong River is the main source of eutrophication for Xiamen Bay, providing more than 4 × 104 tonnes (Mg) of N input per year. The atmospheric N dry deposition provided more than 2.2 × 103 Mg of DIN input per year, which accounts for ~3.4–6.3% of the Jiulong River DIN input in the coastal Xiamen. Discussion The ratio of atmospheric nitrogen deposition to nitrogen enrichment from Jiulong River varied from 0.21 to 0.40, indicating that atmospheric nitrogen deposition was an important contributor to the coastal nutrient in Xiamen. This study provides an insight into the major sources of N and P and highlights the importance of atmospheric nitrogen deposition to the DIN in the coastal city Xiamen.
The magneto-mechanical coupling of multiphase magnetorheological elastomers
Authors: Barron III Edward J , Williams Ella T , Lazarus Nathan , Bartlett Michael D
Published: January 2025

Magnetorheological elastomers (MREs) are soft magnetic composites that achieve tunable changes in stiffness and damping in the presence of a magnetic field. Rigid particle composite (RC) MREs have been studied for decades for their potential applications to automotive dampers and robotic systems. Recently, magnetic fluid composite (FC) MREs have been developed which utilize magnetic fluids as inclusions to elastomers. An investigation into how inclusion phase affects magneto-mechanical performance may greatly improve MRE design capabilities. Here we experimentally evaluate the impact of solid and liquid magnetic inclusions on MRE properties, construct a simple model that captures the performance of diverse MRE material architectures, and demonstrate the use of the model to create material design maps relating the material structure, zero-field properties, and applied field to the elastic modulus and specific loss. The magneto-mechanical response is evaluated for three material architectures: RC, FC, and hybrid composite MREs that use solid particles, magnetic fluids, and a combination of the two as inclusions respectively. The model is developed through magnetic and mechanical energy principles, which suggests that the phase of the magnetic inclusions impacts the change in energy density during deformation. We show that the magneto-mechanical coupling factor is dependent on the zero-field properties of the composites, which allows for the development of material design maps to inform the fabrication of MREs based on desired properties.
Precise multi-satellite orbit and geodetic parameter determination using satellite laser ranging observations from LAGEOS, Etalon and newly launched LARES-2
Authors: Shao Kai , An Zicong , Yang Yan , Yi Bin
Published: January 2025

Determining precise multi-satellite orbits and geodetic parameters using satellite laser ranging (SLR) observations of spherical laser geodetic satellites is essential for high-accuracy geodetic scientific applications. Weekly multi-satellite combined solutions for satellite orbits, station coordinates and earth rotation parameters (ERPs) using SLR observations from LAGEOS, Etalon and newly launched LARES-2 satellites are achieved using a self-developed software function based on a new processing strategy. We present an in-depth accuracy analysis of the satellite orbits and geodetic parameters determined from the combined solution of LAGEOS-Etalon and LAGEOS-Etalon-LARES-2, in which the impact of two years of LARES-2 SLR observations is mainly studied. The root mean square (RMS) value of post-fit residuals is 0.81 cm for LARES-2, which is comparable to or slightly smaller than that of the LAGEOS and Etalon satellites. The statistics of the differences in overlapping orbit and external orbit comparison are performed for orbit accuracy assessment. For LAGEOS and Etalon, the results of overlapping orbit and external orbit comparison present similar conclusions. The mean of the RMS values of orbit difference for LAGEOS is about 3 cm in the three-dimensional (3D) direction, and less than 1 cm in the radial (R) direction. The mean RMS value of orbit difference for Etalon is about 15 cm in the 3D direction, and less than 3 cm in the R direction. The inclusion of LARES-2 SLR observations can slightly improve the orbit accuracy of Etalon. For LARES-2, the mean RMS values of overlapping orbit difference are 1.79 cm and 0.29 cm in the 3D and R directions, respectively, which are smaller than those for LAGEOS. Moreover, the stability and accuracy of the estimated station coordinates and ERPs are improved after adding LARES-2 SLR observations to multi-satellite combined solutions.
Unbounded solutions for the Muskat problem
Authors: Sánchez Omar
Published: January 2025

We prove the local existence of solutions of the form

x
2

+
c
t
+
g
,

with

g
∈

H
s

(

R

)

and

s
⩾
3
,

for the Muskat problem in the stable regime. We use energy methods to obtain a bound of g in Sobolev spaces. In the proof we deal with the loss of the Rayleigh–Taylor condition at infinity and a new structure of the kernels in the equation. Remarkably, these solutions grow quadratically at infinity.
Exploring solar cell applications of halide perovskites through a DFT analysis
Authors: El Moutaouakil Ayoub , Saaoud Mohamed , Drissi Lalla Btissam
Published: January 2025

This study probes the potential of lead-free perovskite solar cells (PSCs) as a promising alternative to their lead-based counterparts. It focuses on harnessing halogenated perovskites (HP) Cs
3
XI
6, where X represents In, Tl, Al, Ga and B, by employing both GGA approximation and the inclusion of mBJ correction within the framework of DFT. The analysis of substituents effects on energy band structure reveals that the compounds closely approach the esteemed Shockley–Queisser limit, indicating their potential for efficient photovoltaic conversion. Remarkably, the optical absorption coefficients of the HP materials under scrutiny approximate 103 cm−1. Among the HP compounds studied, Cs
3
InI
6, Cs
3
TlI
6, and Cs
3
GaI
6 emerge as particularly promising candidates for solar cell technology and various photovoltaic applications. These findings not only underscore the viability of lead-free perovskite solar cells but also offer valuable insights into the design and optimization of materials for sustainable energy solutions.
64 nm continuously tunable graphene-mode-locked erbium-doped fiber laser by tunable bandpass filter
Authors: Muhammad Farah Diana , Azis Raba’ah Syahidah , Ahmad Fauzan
Published: January 2025

This paper demonstrates and characterizes a tunable wavelength ultrafast erbium-doped fiber laser (EDFL), enabled by a tunable bandpass filter (TBF) and mode-locked with a graphene thin film as the saturable absorber. The laser’s wavelength can be continuously tuned from 1507.5 nm to 1571.3 nm, covering a broad range of 63.8 nm. Fourteen distinct wavelengths, spaced at 5 nm intervals, are recorded. The variation in bandwidth and pulse width across these wavelengths reveals values ranging from 0.5 nm to 0.8 nm and from 3.9 ps to 6.6 ps, respectively, all at a fixed repetition rate of 12.9 MHz. Analysis of the time-bandwidth product shows the lowest value of 0.34 at 1567.5 nm and the highest value of 0.46 at 1507.5 nm. These findings enhance the understanding of wavelength-tunable graphene-based mode-locked EDFL operation, specifically through the spectral filtering effect achieved with a TBF.
Fixing the AdS3 metric from pure state entanglement entropies of CFT2
*
Authors: Wang 王 Peng 鹏 , Wu 伍 Houwen 厚文 , Yang 杨 Haitang 海棠
Published: January 2025

In this study, based on the Ryu-Takayanagi formula, by identifying the pure state UV and IR entanglement entropies of a perturbed CFT2 with geodesic lengths in the bulk, we demonstrate that the dual geometry is uniquely determined to be asymptotically AdS3. The pure AdS3 geometry is recovered by taking the massless limit of the system. Our derivations hold in both static and covariant scenarios.
Characteristics of polaritonic interactions at chiral loaded temperature-sensitive material (TSM) interfaces
Authors: Ali Ahtisham , Yaqoob Muhammad Zeshan , Alkanhal Majeed A S , Ghaffar Abdul , Khan Yasin
Published: January 2025

Polaritonic interactions are pivotal in advancing sensing technologies, optical devices, and waveguides. This study presents a theoretical investigation into polaritonic interactions at the interface of chiral-loaded temperature-sensitive materials (TSMs). Indium antimonide (InSb), known for its temperature-dependent phase-transition optical properties, is utilized as the TSM. The electromagnetic (EM) behavior of InSb is described using the extended Drude model, while the isotropic chiral medium is characterized through coupled constitutive relations. By applying tangential boundary conditions for EM field continuity at the chiral–InSb interface, the dispersion relation governing hybrid polaritons is derived. Numerical computations performed in Wolfram Mathematica, utilizing the contour plot technique, reveal the dispersion characteristics, effective mode index, and field distributions under varying temperatures. The findings demonstrate the existence of two distinct polaritonic regimes: (i) hybrid polariton–phonon coupling at temperatures below 200 K, and (ii) hybrid polariton–plasmon coupling at temperatures exceeding 260 K. Additionally, the effects of chirality and temperature on the dispersion curves, effective mode indices, and field profiles are systematically analyzed. Results reveal that polaritonic surface modes can be dynamically tuned by manipulating external temperature and material chirality. These insights hold significant promise for the development of temperature-responsive terahertz-infrared (THz-IR) sensors, enantiomeric detectors, thermo-optical surface waveguides, and near-field imaging systems.
Towards enhanced precision in thermometry with nonlinear qubits
Authors: Deffner Sebastian
Published: January 2025

Quantum thermometry refers to the study of measuring ultra-low temperatures in quantum systems. The precision of such a quantum thermometer is limited by the degree to which temperature can be estimated by quantum measurements. More precisely, the maximal precision is given by the inverse of the quantum Fisher information. In the present analysis, we show that quantum thermometers that are described by nonlinear Schrödinger equations allow for a significantly enhanced precision, that means larger quantum Fisher information. This is demonstrated for a variety of pedagogical scenarios consisting of single and two-qubits systems. The enhancement in precision is indicated by non-vanishing quantum speed limits, which originate in the fact that the thermal, Gibbs state is typically not invariant under the nonlinear equations of motion.
The Spanish American Concordats (1821–1875)
Authors: Mijangos y González Pablo
Published: January 2025

In his chapter on the Spanish American Concordats, Pablo Mijangos argues that these little-studied diplomatic agreements between the government and the Holy See played an important role in the early republicanera. The agreements focused on handling ecclesiastical affairs in the new nation-states. However, they are also crucial because they presage the relationship of international law and nation-state governments that would evolve in the twentieth century, and hold important lessons about soft power and international agreements. Mijangos builds his arguments from primary documents and other archival material, engaging with historical and legal debates.
Law and Development in/from Latin America
Authors: Mota Prado Mariana
Published: January 2025

The chapter explores three case studies that illustrate moments in which scholars and policy makers in Latin America have offered contributions to the international development discourse. While focusing on contributions that proposed or led to legal reforms, and therefore could be labelled as “law and development”, the chapter maps into different moments of the international development discourse. Especifically, the case studies cover : dependency theory, Hernando Soto’s writing on property rights and bureaucratic reforms, and conditional cash transfers to explore Latin American contributions to three different phases of the intellectual history of international development. Each case reveals a distinct way in which “local” ideas interact with “international” paradigms, uncovering the tensions between competing claims of universalism and contextualization that has characterized “law and development” scholarship since its inception..
Critical Approaches to International Law in Latin America
Authors: Galindo George Rodrigo Bandeira
Published: January 2025

Latin America was one of the earliest regions of the world to achieve independence from European colonization, but it was a latecomer to TWAIL (Third World approaches to international law). This is in part because of Latin American scholars’ commitment to positivism and concomitant skepticism about interdisciplinarity. George Galindo explores the region’s recent engagement, tracing how a growing group of scholars have raised friendly challenges to TWAIL, such as pushing TWAIL to engage further with the Indigenous peoples of the Americas and legal pluralism. The chapter closes with a review of theorists who view the project of Latin American international law as an exclusionary criollo construct.
Feminisms and International Law in Latin America
Authors: Micaela Alterio Ana
Published: January 2025

This chapter discusses the judgment of Vicky Hernadez v. Honduras, issued by the Inter-American Court of Human Rights in 2021, to explore disputes between Latin American feminisms. The judgment pushes against the limits of binary approaches in human rights law, using an evolutionary interpretative approach to extend human rights protection to transgender people. The author applauds the decision as having the potential to shatter “the stability” of essentialist legal systems. However, she notes with concern that the dissents are based on a more exclusionary view of feminism, thus reflecting disputes within the feminist movement that continue to play out in the region and that seek to influence the interpretation of international human rights law.

.
The Dynamic Relationship between Latin American Legal Professionals and International Law
Authors: Gómez Manuel A
Published: January 2025

This chapter explores the enduring and complex connection between Latin American legal professionals and international law in the early decades of the twenty-first century. It delves into two key developments: the emergence of an international dispute resolution community and the expansion of clinical legal education into modern international law-related domains. These examples shed light on the way that the legal professions in the region have responded to and have evolved as a result of the growing significance of legal issues that extend beyond national boundaries and how porous the invisible line is that purports to divide international and domestic legal practice.
Latin America as a Laboratory of Transitional Justice
Authors: Chehtman Alejandro
Published: January 2025

This chapter provides a detailed mapping of legal and institutional innovations in the field of transitional justice in Latin America. It explores the forces and actors that led to establishing the first truth commission and the seminal Junta’s trials in Argentina. The chapter further dissects the key innovations in truth, justice, and peace that allow Latin American interventions against mass atrocity to be construed as a laboratory of experimentation and innovation. Ultimately, the chapter advances three claims. First, it describes the key dynamics between victims’ organizations, legal scholars, and judicial officers that underpin these experiments. Second, it reflects the regional scope of the dialogue and cross-fertilization between initiatives. Third, it articulates how relevant actors reinterpreted and used human rights discourse to pursue their grievances, transforming it into a mainstream, arguably dominant framework to address not only state repression but all forms of injustice.
Introduction
Authors: Giubilini Alberto , Schuklenk Udo , Minerva Francesca , Savulescu Julian
Published: January 2025

This introductory chapter provides an overview of the problem of conscientious objection in health care. Through examples, it illustrates why it is a problem when it is raised in the context of professional activities characterized by a monopoly on provision of certain services. Health care is one of those. The chapter outlines how conscientious objection can impact health care delivery and provides an overview of the main arguments for and against it that will be discussed in the rest of the book, also with reference to jurisdictions that do not include a right to conscientious objection. Importantly, it is explained why arguments against conscientious objection do not need to presuppose any substantive moral view about the procedures to which health care professionals commonly object, such as abortion.
US-China Bipolarity and Conflictual Coexistence
Authors: Tunsjø Øystein
Published: January 2025

As the rivalry between the United States and China increases, decision-makers, scholars, and the media are debating whether a new cold war is emerging or whether it can be avoided. This chapter contends that the world has entered a new superpower rivalry that is distinct from the Cold War. If the contemporary bipolar system does not share the Cold War characteristics of the previous bipolar system, what, then, are the characteristics of this new bipolar system? It is argued that the United States and China are in a new era of conflictual coexistence where patterns of behavior differ from the Cold War and secondary states have more flexibility.
The Limits of China’s Economic Rise
Authors: Dollar David
Published: January 2025

China’s increasing influence in the world owes a lot to its remarkable economic performance. This chapter focuses on four factors that will influence how well China realizes its considerable catch-up potential vis-à-vis the United States. First is the demographic challenge. Low fertility, aided by the one-child policy, means that the country’s labor force has peaked and will now decline. Second, China is fortunate to have a high savings and investment rate that funds its development. Third, China faces a severe water crisis. The fourth issue is energy efficiency and carbon emissions. Unless China does an exceptional job handling these challenges, its growth rate is likely to slow. Nevertheless, China’s considerable catch-up potential means that its economy will still probably end up modestly larger than the United States in a few decades—but not overwhelmingly so.
The “Venture Capital State”
Authors: Kroeber Arthur R
Published: January 2025

China’s economic rise, state-led technological progress, and authoritarian political system have spurred fears that it could destabilize the global order. Systemic differences between China and the United States and its allies are permanent, but China’s economic outperformance is not. China’s development strategy under Xi Jinping relies heavily on investment in technology-intensive manufacturing while doing little to improve overall efficiency. On current policies, average annual gross domestic product growth should fall to around 3%, and China will probably fail to overtake the United States as the world’s largest economy. But it will keep making rapid progress in key technologies, and this progress will be seen as a threat by the United States and its allies. Because most countries have a strong interest in deep economic ties with both powers, the United States and China will not form exclusive blocs as in the Cold War but will compete in overlapping networks of influence.
Will US-PRC Military Competition Go Global?
Authors: Christensen Thomas J
Published: January 2025

The US–People’s Republic of China (PRC) strategic competition differs from the early phases of the US-Soviet Cold War. There is now a high degree of economic interdependence not only between the two leading powers but also between US allies and China. The United States and China have not been as active in exporting their respective ideologies as were the superpowers in the early Cold War. For these reasons, the world seems less likely to break into clearly delineated and opposing alliance blocs than it did in the 1950s. The Russian invasion of Ukraine and China’s generally supportive reaction to it, however, have weakened some of the economic and political factors that have made the contemporary international system distinct from that of the early Cold War. This chapter explores the factors that could lead to a more global and more conflict-prone competition between a rising China and the United States.
The Russian Invasion of Ukraine and the Sino-Russian Partnership
Authors: Wishnick Elizabeth
Published: January 2025

This chapter examines the benefits Chinese officials believe their country derives from the Sino-Russian partnership as well as its limitations in the broader context of a globalized world from which China greatly benefits economically. This is not the Cold War alliance of the 1950s—today China seeks Russian partnership to adjust the rules of the global order to accommodate the preferences and needs of authoritarian regimes as well as to buttress Chinese global economic and security positions. Although censorship has prohibited criticism of Sino-Russian relations, some prominent retired officials have stated publicly that Russia is a liability and a few leading scholars have criticized Russian policies. Despite evidence of misgivings in some advisory circles, Xi is unlikely to change course.
China-Russia Rapprochement
Authors: Ekman Alice
Published: January 2025

Sino-Russian rapprochement has been accelerating since the annexation of Crimea in 2014 and has not been put into question since the beginning of Russia’s invasion of Ukraine on February 24, 2022. This chapter looks at the political and geostrategic drivers of the rapprochement. In particular, the analysis takes into account China’s coalition-building strategy under Xi Jinping and the role of Russia within this strategy. It argues that, even if significant imbalances remain between the two countries, the Sino-Russian partnership is likely to continue to consolidate at a rapid pace in the coming years, as China considers Russia as a core pillar of its coalition-building strategy in a context of deep and multilayered rivalry with the United States.
Hobbes's Two Sciences
Authors: Adams Marcus P
Published: January 2025

Seventeenth-century thinker Thomas Hobbes maintained that his philosophy constituted a unified system, but in what precise sense did he think that the branches of his philosophy were unified? This question has provoked extensive scholarship over the last half-century. Not only is answering it essential to understanding Hobbes’s philosophy generally, but how one answers it significantly impacts our understanding of the Leviathan, his most influential work, and of the Laws of Nature, the foundation of Hobbesian political philosophy. Hobbes’s Two Sciences: Politics, Geometry, and the Structure of Philosophy answers the question by situating Hobbes’s politics within his account of scientific knowledge as constructed by humans—an epistemology founded on the idea that makers have special access to causal knowledge—and by demonstrating that the relationship between pure and mixed mathematics provided him with a model for thinking about relationships between geometry and natural philosophy and between politics and history. This understanding of Hobbes’s systematic philosophy impacts several long-standing areas of scholarship on Hobbes and the history of early modern philosophy.
Introduction: The Unity of Hobbes’s Philosophy
Authors: Adams Marcus P
Published: January 2025

This chapter introduces a puzzle in Hobbes scholarship: how do the parts of Hobbes’s philosophy fit together? It summarizes and distinguishes two dominant approaches—the deductivist view and the disunity view—and outlines significant flaws each view faces. It then describes desiderata for any account of how Hobbes’s philosophy is unified and shows how the view to be articulated in the remaining chapters—the maker’s knowledge view—meets each desideratum and provides a way to understand Hobbes’s philosophy as unified without being reductionistic. The chapter also contrasts the maker’s knowledge view with an influential account of Hobbes’s philosophical development and argues against seeing eloquence as part of Hobbes’s civil science as such. Rather than eloquence, the maker’s knowledge view understands Hobbes as providing different ways of demonstrating civil science, whether in a synthetic demonstration, as in Leviathan, or as “one easie sum” for the “meanest brute” unable to follow such a demonstration.
Prudential Knowledge from Sense and the Mechanical Mind
Authors: Adams Marcus P
Published: January 2025

This chapter begins a two-part account of Hobbes’s epistemology by focusing first upon what Hobbes frequently identifies with the Latin term cognitio: human and non-human knowledge founded in conceptions received in sense. The chapter addresses (1) the source of Hobbesian cognitio from sense through prudence as particular conceptions among which a knower judges “similitudes” (an inference from many instances to all or most of some kind), (2) Hobbes’s explanation for this behavior as seeking to bring about antecedents of desired consequents, and (3) the role that language plays in allowing human knowers to mark conceptions with names, form contingent propositions and syllogisms using those propositions, and raise conceptions in others by using names as public signs.
Hobbesian Natural Philosophy as Mixed Mathematics
Authors: Adams Marcus P
Published: January 2025

Chapter 5 offers an alternative account of the relationship of Hobbesian geometry to natural philosophy by arguing that mixed mathematics provides Hobbes with a model for thinking about it. In mixed-mathematics disciplines, such as optics, harmonics, and mechanics, one may borrow causal principles from one science and use them in another science without a deductive relationship. In Hobbes’s descriptions and practice of natural philosophy, one may appeal to everyday experience or experiments for the demonstration that something happens (the “that”) and borrow the cause (the “why”) from geometry. The chapter considers Hobbes’s comments concerning and relation to Aristotelian subalternate sciences and to Isaac Barrow’s broadening of mixed mathematics, contrasting these affinities to Hobbes’s contemporary John Wallis’s understanding. According to Hobbes, maker’s knowledge from geometry provides the “why” in mixed-mathematical explanations, and any explanation must be constrained by a priori principles of motion. The chapter examines three explanations in Hobbes’s natural philosophy and displays his behavior of borrowing and citing geometrical principles and then mixing those principles with appeals to experience. The chapter also contrasts the benefits of the mixed mathematics view with weaknesses of Shapin and Schaffer’s (1985) account of Hobbes’s dispute with Robert Boyle.
Experience in Hobbesian Civil Philosophy and Civil History
Authors: Adams Marcus P
Published: January 2025

Although Hobbes’s interests in the historical past are various and span his corpus, chapter 6 examines why Hobbes thought it was legitimate to borrow causal principles from civil philosophy within certain parts of historical explanations (called Hobbesian “historiography” in the chapter). This focus on historiography is motivated by a tension in Hobbes’s own view: although he places natural history and political history outside of the “subject” of philosophy because they are merely knowledge from sense, he admits that they are “useful” and even “necessary” for philosophy. Rather than understanding this as asserting a need for preparation in history by philosophers, chapter 6 shows that in an explanation of the historical past, both political history and civil philosophy (one of Hobbes’s two sciences) play essential roles: while political history demonstrates ‘that’ some event has occurred, civil philosophy provides the reason ‘why’ with a borrowed causal principle. Seeing this connection between civil philosophy and historiography illuminates the source of tension in Hobbes’s seemingly paradoxical statements about the place of history and shows that the explanations in chapter 45 of Leviathan Part IV are structurally analogous to those in the natural philosophy of De corpore Part IV, and so likewise are the explanations in the historiographical dialogue Behemoth and the natural-philosophical Dialogus Physicus.