We propose a deterministic scheme for establishing hybrid Einstein-Podolsky-Rosen (EPR) entanglement channel between a macroscopic mechanical oscillator and a magnon mode in a distant yttrium-iron-garnet (YIG) sphere across about 10 GHz of frequency difference. The system consists of a driven electromechanical cavity which is unidirectionally coupled to a distant electromagnonical cavity inside which a YIG sphere is placed. We find that far beyond the sideband-resolved regime in the electromechanical subsystem, stationary phonon-magnon EPR entanglement can be achieved. This is realized by utilizing the output field of the electromechanical cavity being an intermediary which distributes the electromechanical entanglement to the magnons, thus establishing the remote phonon-magnon entanglement. The EPR entanglement is strong enough such that phonon-magnon quantum steering can be attainable in an asymmetric manner. This long-distance macroscopic hybrid EPR entanglement and steering enable potential applications not only in fundamental tests of quantum mechanics at the macroscale, but also in quantum networking and one-sided device-independent quantum cryptography based on magnonics and electromechanics.

Combining elastic incoherent neutron scattering experiments at different resolutions with molecular dynamics simulations, we report the observation of a proteinlike dynamical transition in linear chains of poly($N$-isopropylacrylamide). We identify the onset of the transition at a temperature $T_d$ of about 225 K. Due to a global fit procedure, we find quantitative agreement between measured and calculated polymer mean-squared displacements at all temperatures and time resolutions. Our results confirm the generality of the dynamical transition in macromolecular systems in aqueous environments, independently of the internal polymer topology.

For fundamentally characterizing the effect of hierarchical structure in granular matter, a set of compression-relaxation tests for dust particles and glass beads confined in a cylindrical cell was performed. The typical diameter of both grains is approximately 1 mm. However, dust particles are produced by binding tiny ($\sim 5\mu \mathrm{m}$) glass beads. The granular columns were compressed with a piston until reaching a maximum load force of 20 N with a constant compression rate $v$ ($0.17\le v\le 2000\mu \mathrm{m}{\mathrm{s}}^{-1}$). After that, the piston was stopped and the relaxation process was quantified. From the experimental results, we found that the compression force $F$ nonlinearly increases with the increase of compression stroke $z$ depending on particles. Besides, periodic undulation and sudden force drops were observed on $F\left(z\right)$ in dust particles and glass beads, respectively. The relaxation process was characterized by an exponential decay of stress followed by a logarithmic dependence one in both kinds of particles. These experimental findings are the main point in this study. To understand the underlying physics governing the compression mechanics, we assumed empirical forms of $F\left(z\right)$; $F\propto z^{\alpha }$ for dust particles and $F\propto exp(z/z_G)$ for glass beads ($\alpha =2.4$ and $z_G=70\mu \mathrm{m}$). Then, we found that the growing manners of periodic undulation and force drops were identical to those of mean compression forces, i.e., power law in dust particles and exponential in glass beads. In addition, the undulation amplitude and wavelength decreased as $v$ increased in dust-particle compression. On the basis of experimental results and the difference between dust particles and glass beads, we also discuss the origin of undulation and the physical meaning of granular-compression models used in engineering fields.

Recently, it was shown that the multipolar Kondo problem, wherein a quantum impurity carrying higher-rank multipolar moments interacts with conduction electrons, leads to novel non-Fermi liquid states. Because of the multipolar character of the local moments, the form of the interaction with conduction electrons is strongly dependent on the orbital symmetry of the conduction electrons via crystalline symmetry constraints. This suggests that there may exist a variety of different non-Fermi liquid states in generic multipolar Kondo problems depending on the character of conduction electrons. In this work, using renormalization group analysis, we investigate a model where the multipolar local moment is coupled to conduction electrons with two different orbital-symmetry components, namely, $p$-wave and $f$-wave symmetries. When each orbital-symmetry component is present alone, non-Fermi liquid states with exactly the same thermodynamic singularities appear. When both orbital-symmetry components are allowed, however, a completely different non-Fermi liquid state arises via the quantum fluctuations in the mixed scattering channels. This remarkable result suggests that the multipolar Kondo problem presents unique opportunities for the discovery of unexpected non-Fermi liquid states.

The propulsion of living microorganisms ultimately relies on viscous drag for body-fluid interactions. The self-locomotion in superfluids such as ${}^4\mathrm{He}$ is deemed impossible due to the apparent lack of viscous resistance. Here, we investigate the self-propulsion of a Janus (two-face) light-absorbing particle suspended in superfluid helium ${}^4\mathrm{He}$ (He-II). The particle is energized by the heat flux due to the absorption of light from an external source. We show that a quantum mechanical propulsion force originates due to the transformation of the superfluid to a normal fluid on the heated particle face. The theoretical analysis is supported by the numerical solution of the Ginzburg-Landau-Khalatnikov model for a superfluid. Our results shed light on the dynamics of inclusions in a superfluid and stimulate experiments.

We investigate a heat engine under an adiabatic (Thouless) pumping process. In this process, the extracted work and lower bound on dissipated availability are characterized by a vector potential and a Riemannian metric tensor, respectively. We derive a trade-off relation between the power and effective efficiency. We also explicitly calculate the trade-off relation as well as the power and effective efficiency for a spin-boson model coupled to two reservoirs.

The hematopoietic stem cells (HSCs) can differentiate to myeloid and lymphoid lineages, which lead to more specific differentiated cells. This cell fate decision process is governed by an underlying gene regulatory network. However, its underlying mechanism remains to be fully clarified. In this work, based on a gene regulatory network of HSC differentiation, we built a dynamical model and developed an optimization approach to infer model parameters by fitting experimental data quantitatively. We mapped out the potential landscape of HSC differentiation and identified multistable cell states observed in experiments, including multipotent progenitor, B-cell, and macrophage. Interestingly, we also identified one new intermediate cell state on the landscape, which plays a critical role on the cellular transdifferentiation. By calculating the transition action among different attractor states, we quantified kinetic transition paths for differentiation and transdifferentiation between different cell states and identified key genes and regulations during these transition processes. Our work provides a general approach to construct a gene regulatory network model based on experimental data and new insights into the roles of intermediate states on the transdifferentiation process in HSC development.

With a view toward a fracton theory in condensed matter, we introduce a higher-moment polynomial degree-p global symmetry, acting on complex scalar/vector/tensor fields (e.g., ordinary or vector global symmetry for $\mathrm{p}=0$ and $\mathrm{p}=1$ respectively). We relate this higher-moment global symmetry of $n$-dimensional space, to a lower degree [either ordinary or higher-moment, e.g., degree-(p-$\ell$)] subdimensional or subsystem global symmetry on layers of $(n-\ell )$-submanifolds. These submanifolds are algebraic affine varieties (i.e., solutions of polynomials). The structure of layers of submanifolds as subvarieties can be studied via mathematical tools of embedding, foliation, and algebraic geometry. We also generalize Noether's theorem for this higher-moment polynomial global symmetry. We can promote the higher-moment global symmetry to a local symmetry and derive a new family of higher-rank-m symmetric tensor gauge theory by gauging, with $\mathrm{m}=\mathrm{p}+1$. By further gauging a discrete ${\mathbb{Z}}_2^C$ charge conjugation (particle-hole) symmetry, we derive a general class of rank-m tensor non-Abelian gauge field theory (the gauge structure is noncommutative thus non-Abelian but not an ordinary group): a hybrid class of (symmetric or nonsymmetric) higher-rank-m tensor gauge theory and antisymmetric tensor topological field theory, generalizing Wang and Xu [Ann. Phys. 424, 168370 (2021)], interplaying between gapless and gapped sectors.

Rapid progress in noisy intermediate-scale quantum (NISQ) computing technology has led to the development of novel resource-efficient hybrid quantum-classical algorithms, such as the variational quantum eigensolver (VQE), that can address open challenges in quantum chemistry, physics, and material science. Proof-of-principle quantum chemistry simulations for small molecules have been demonstrated on NISQ devices. While several approaches have been theoretically proposed for correlated materials, NISQ simulations of interacting periodic models on current quantum devices have not yet been demonstrated. Here, we develop a hybrid quantum-classical simulation framework for correlated electron systems based on the Gutzwiller variational embedding approach. We implement this framework on Rigetti quantum processing units (QPUs) and apply it to the periodic Anderson model, which describes a correlated heavy electron band hybridizing with noninteracting conduction electrons. Our simulation results quantitatively reproduce the known ground state quantum phase diagram including metallic, Kondo and Mott insulating phases. This is the first fully self-consistent hybrid quantum-classical simulation of an infinite correlated lattice model executed on QPUs, demonstrating that the Gutzwiller hybrid quantum-classical embedding framework is a powerful approach to simulate correlated materials on NISQ hardware. This benchmark study also puts forth a concrete pathway towards practical quantum advantage on NISQ devices.

Dirac-Weyl semimetals are unique three-dimensional (3D) phases of matter with gapless electrons and novel electrodynamic properties believed to be robust against weak perturbations. Here, we unveil the crucial influence of the disorder statistics and impurity diversity in the stability of incompressible electrons in 3D semimetals. Focusing on the critical role played by rare impurity configurations, we show that the abundance of low-energy resonances in the presence of diluted random potential wells endows rare localized zero-energy modes with statistical significance, thus lifting the nodal density of states. The strong nonperturbative effect here reported converts the 3D Dirac-Weyl semimetal into a compressible metal even at the lowest impurity densities. Our analytical results are validated by high-resolution real-space simulations in record-large 3D lattices with up to 536 000 000 orbitals.

With the rapid progress in quantum hardware, there has been an increased interest in new quantum algorithms to describe complex many-body systems searching for the still-elusive goal of “useful quantum advantage.” Surprisingly, quantum algorithms for the treatment of open quantum systems (OQSs) have remained underexplored, in part due to the inherent challenges of mapping non-unitary evolution into the framework of unitary gates. Evolving an open system unitarily necessitates dilation into a new effective system to incorporate critical environmental degrees of freedom. In this context, we present and validate a new quantum algorithm to treat non-Markovian dynamics in OQSs built on the ensemble of Lindblad's trajectories approach, invoking the Sz.-Nagy dilation theorem. Here we demonstrate our algorithm on the Jaynes-Cummings model in the strong-coupling and detuned regimes, relevant in quantum optics and driven quantum system studies. This algorithm, a key step towards generalized modeling of non-Markovian dynamics on a noisy-quantum device, captures a broad class of dynamics and opens up a new direction in OQS problems.

What is the fate of the ground state of a two-dimensional electron system at very low Landau level filling factors $\left(\nu \right)$ where interaction reigns supreme? An ordered array of electrons, the so-called Wigner crystal, has long been believed to be the answer. It was in fact the search for the elusive Wigner crystal that led to the discovery of an unexpected, incompressible liquid state, namely the fractional quantum Hall state at $\nu =1/3$. Understanding the competition between the liquid and solid ground states has since remained an active field of fundamental research. Here we report experimental data for a new two-dimensional system where the electrons are confined to an AlAs quantum well. The exceptionally high quality of the samples and the large electron effective mass allow us to determine the liquid-solid phase diagram for the two-dimensional electrons in a large range of filling factors near $\simeq 1/3$ and $\simeq 1/5$. The data and their comparison with an available theoretical phase diagram reveal the crucial role of Landau level mixing and finite electron layer thickness in determining the prevailing ground states.

The electron-doped cuprates are usually characterized by a more robust antiferromagnetic phase and a much narrower superconducting (SC) dome than those of the hole-doped counterparts. Recently, bulk single crystals of ${\text{Pr}}_{1.3-x}{\text{La}}_{0.7}{\text{Ce}}_x{\text{CuO}}_{4-\delta }$ (PLCCO) prepared by the protect annealing method have been studied extensively and revealed many intriguing properties that were different from those obtained from samples annealed by the conventional methods. Here we report on a systematic angle-resolved photoemission spectroscopy study of PLCCO single crystals after protect annealing. The results indicate that the actual electron concentration ($n_{\text{FS}}$) estimated from the Fermi-surface area is significantly larger than the Ce concentration $x$ and the new $n_{\text{FS}}$-based SC dome of PLCCO is more extended towards the overdoped side than the $x$-based SC dome derived for samples prepared using the conventional annealing method.

Material realization of the non-Abelian Kitaev spin liquid phase—an example of Ising topological order (ITO)—has been the subject of intense research in recent years. The $4d$ honeycomb Mott insulator $\alpha \text{−}{\mathrm{RuCl}}_3$ has emerged as a leading candidate, as it enters a field-induced magnetically disordered state where a half-integer quantized thermal Hall conductivity ${\kappa }_{xy}$ was reported. Further, a recent report of a sign change in the quantized ${\kappa }_{xy}$ across a certain crystallographic direction is strong evidence for a topological phase transition between two ITOs with opposite Chern numbers. Although this is a fascinating result, independent verification remains elusive, and one may ask if there is a thermodynamic quantity sensitive to the phase transition. Here we propose that the magnetotropic coefficient $k$ would serve such a purpose. We report a singular feature in $k$ that indicates a topological phase transition across the $\widehat{\mathit{b}}$-axis where ITO is prohibited by a $C_2$ symmetry. If the transition in $\alpha \text{−}{\mathrm{RuCl}}_3$ is indeed a direct transition between ITOs, or is a more broad realization of a topological phase transition, then this feature in $k$ should be observable. Implications of $C_2$ symmetry on other experimental quantities are also discussed.

We study the dynamical behavior of ultracold fermionic atoms loaded into an optical lattice under the presence of an effective magnetic flux, induced by spin-orbit-coupled laser driving. At half-filling, the resulting system can emulate a variety of iconic spin-1/2 models such as an Ising model, an $XY$ model, a generic $XXZ$ model with arbitrary anisotropy, or a collective one-axis twisting model. The validity of these different spin models is examined across the parameter space of flux and driving strength. In addition, there is a parameter regime where the system exhibits chiral, persistent features in the long-time dynamics. We explore these properties and discuss the role played by the system's symmetries. We also discuss experimentally viable implementations.

Precessing magnetization is known to generate and inject pure spin currents to adjacent materials by the spin pumping effect. However, the generation of the pure spin current is the only case of the spin pumping at the spin-conserving interface. The charge current is usually accompanied by the usual spin pumping effect at the spin-nonconserving interface in general. In this paper, we consider systems where spin can be scattered and flipped by the Elliott-Yafet-like process at interfaces. For these systems, we investigate the interface-generated charge pumping by using the adiabatic quantum pumping theory. We present the analytic expressions for this pumped charge current in terms of the generalized mixing conductances. For the system that we consider, we find interestingly that the connection between the spin pumping effects and magnetoelectronic circuit theory, which has been demonstrated for the spin-conserving systems, can be extended in spin-nonconserving interfaces, and we show that the pumped charge current generated from the interfacial spin-flip potential can be understood in the context of the generalized spin conductance tensors suggested from the generalized magnetoelectronic circuit theory. We also compare the pumped charge current with other mechanisms that generate a charge current or electric voltage in the presence of the precessing magnetization.

A fundamental feature of complex biological systems is the ability to form feedback interactions with their environment. A prominent model for studying such interactions is reservoir computing, where learning acts on low-dimensional bottlenecks. Despite the simplicity of this learning scheme, the factors contributing to or hindering the success of training in reservoir networks are in general not well understood. In this work, we study nonlinear feedback networks trained to generate a sinusoidal signal, and analyze how learning performance is shaped by the interplay between internal network dynamics and target properties. By performing exact mathematical analysis of linearized networks, we predict that learning performance is maximized when the target is characterized by an optimal, intermediate frequency which monotonically decreases with the strength of the internal reservoir connectivity. At the optimal frequency, the reservoir representation of the target signal is high-dimensional, desynchronized, and thus maximally robust to noise. We show that our predictions successfully capture the qualitative behavior of performance in nonlinear networks. Moreover, we find that the relationship between internal representations and performance can be further exploited in trained nonlinear networks to explain behaviors which do not have a linear counterpart. Our results indicate that a major determinant of learning success is the quality of the internal representation of the target, which in turn is shaped by an interplay between parameters controlling the internal network and those defining the task.

We study a connection between chemical thermodynamics and information geometry. We clarify a relation between the Gibbs free energy of an ideal dilute solution and an information geometric quantity called an $f$ divergence. From this relation, we derive information geometric inequalities that give a speed limit for the changing rate of the Gibbs free energy and a general bound of chemical fluctuations. These information geometric inequalities can be regarded as generalizations of the Cramér–Rao inequality for chemical reaction networks described by rate equations, where un-normalized concentration distributions are of importance rather than probability distributions. They hold true for damped oscillatory reaction networks and systems where the total concentration is not conserved, so that the distribution cannot be normalized. We also formulate a trade-off relation between speed and time on a manifold of concentration distribution by using the geometrical structure induced by the $f$ divergence. Our results apply to both closed and open chemical reaction networks; thus they are widely useful for thermodynamic analysis of chemical systems from the viewpoint of information geometry.

We systematically construct flatbands (FB) for tight-binding models on simple Bravais lattices in space dimension $d\ge 2$ in the presence of a static uniform DC field. Commensurate DC field directions yield irreducible Wannier-Stark (WS) bands in perpendicular dimension $d-1$ with $d$-dimensional eigenfunctions. The irreducible bands turn into dispersionless flatbands in the absence of nearest neighbor hoppings between lattice sites in any direction perpendicular to the DC field. The number of commensurate directions which yield flatbands is of measure one. We arrive at a complete halt of transport, with the DC field prohibiting transport along the field direction, and the flatbands prohibiting transport in all perpendicular directions as well. The anisotropic flatband eigenstates are localizing at least factorially (faster than exponential).

We study the zero-temperature quantum phase diagram for a two-component Bose-Einstein condensate in an optical cavity. The two atomic spin states are Raman coupled by two transverse orthogonally polarized, blue-detuned plane-wave lasers inducing a repulsive cavity potential. For a weak pump the lasers favor a state with homogeneous density and predefined uniform spin direction. When one pump laser is polarized parallel to the cavity mode polarization, the photons coherently scattered into the resonator induce a polarization gradient along the cavity axis, which mediates long-range density-density, spin-density, and spin-spin interactions. We show that the coupled atom-cavity system implements central aspects of the $t\text{−}J\text{−}V\text{−}W$ model with a rich phase diagram. At the mean-field limit we identify at least four qualitatively distinct density- and spin-ordered phases including ferromagnetic and antiferromagnetic order along the cavity axis, which can be controlled via the pump strength and detuning. Real-time observation of amplitude and phase of the emitted fields bears strong signatures of the realized phase and allows for real-time determination of phase transition lines. Together with measurements of the population imbalance, most properties of the phase diagram can be reconstructed.