Absorption of angular momentum from a high intensity laser pulse can lead to the generation of strong axial magnetic fields in plasma. The effect, known as the inverse Faraday effect, can generate kilo-Tesla strength, multipicosecond, axial magnetic fields extending over hundreds of microns in underdense plasma. In this paper we explore the effect with ultrahigh intensity circularly polarized Gaussian beams and linearly polarized orbital angular momentum beams comparing analytic expressions with three-dimensional particle-in-cell simulations. We develop a model for the transverse magnetic field profiles, introduce a model for the temporal decay, and show that while the magnetic field strength is independent of plasma density, it has a strong dependence on the laser beam waist.

We investigate the phenomenon of producing vibration-induced rotational motion in a cylinder filled with achiral rods and being vibrated by an external drive. The arrangement of the rods develops chirality as a result of the interaction of gravity and steric hindrance, which is responsible for the induced motion. A two-rod arrangement is sufficient to generate a persistent motion. The average angular velocity $\langle \omega \rangle$ of the rods at long times varies nonmonotonically with the packing fraction $\varphi$ for a given drive strength $\mathrm{\Gamma }$. Though the precise nature of the variation of $\langle \omega \rangle$ with $\varphi$ depends on the details of the interaction between individual rods, its general characteristics hold true for rods of various materials and geometries. A stochastic model based on the asymmetric simple exclusion process helps in understanding the key features of our experiments.

Single crystals of ${\mathrm{Eu}}_3{\mathrm{InAs}}_3$ have been successfully synthesized by indium flux reactions. ${\mathrm{Eu}}_3{\mathrm{InAs}}_3$ crystallizes in the ${\mathrm{Ca}}_3\mathrm{Al}{\mathrm{As}}_3$-type structure with an orthorhombic space-group $Pnma$. Theoretical calculations indicate that ${\mathrm{Eu}}_3{\mathrm{InAs}}_3$ is a semiconductor with a direct band gap of 0.3 eV. ${\mathrm{Eu}}_3{\mathrm{InAs}}_3$ has large negative Seebeck coefficients in the range of 300–450 μV/K at room temperature. ${\mathrm{Eu}}_3{\mathrm{InAs}}_3$ displays two antiferromagnetic transitions ($T_{N1}=13$ and $T_{N2}=10$ K) for both $H\parallel b$ and $H\perp b$ which can be suppressed by magnetic fields. At 2 K, field-induced ferromagnetic states are reached for both $H\parallel b$ and $H\perp b$. Particularly, the $H\parallel b$ magnetization curves show a plateau at 1/3 of the saturated magnetization and an anomaly at 2/3 of the saturated magnetization. ${\mathrm{Eu}}_3{\mathrm{InAs}}_3$ is a Zintl phase material showing a 1/3 magnetization plateau here.

We experimentally demonstrate fast and high-fidelity geometric control of a quantum system with the brachistochrone method on hybrid spin registers in diamond. Based on the time-optimal universal geometric control, single geometric gates with fidelities over $99.2\%$ on the spin state of the nitrogen-vacancy center are realized with average durations shortened by $21.5\%$ compared with the conventional geometric method. The fidelity of the fast geometric two-qubit gate exceeds $96.5\%$ on the hybrid spin registers. With the fast and high-fidelity universal set of geometric gates available, we implement a quantum entanglement-enhanced phase estimation algorithm and demonstrate the Heisenberg quantum limit of phase estimation at room temperature. Hence our results show that high-fidelity quantum control based on a fast geometric route will be a versatile tool for broad applications of quantum information processing in practice.

Higher rank symmetry and higher moment conservation have been drawn considerable attention from, e.g., subdiffusive transport to fracton topological order. In this paper, we perform a one-loop renormalization group (RG) analysis and show how these phenomena emerge at low energies. We consider a $d$-dimensional model of interacting bosons of $d$ components. At higher rank-symmetric points with conserved angular moments, the $a\mathrm{th}$ bosons have kinetic energy only along the ${\widehat{x}}^a$ direction. Therefore, the symmetric points look highly anisotropic and fine-tuned. By studying RG in a wide vicinity of the symmetric points, we find that symmetry-disallowed kinetic terms tend to be irrelevant within the perturbative regime, which potentially leads to emergent higher rank symmetry and higher moment conservation at the deep infrared limit. While nonperturbative analysis is called for in the future, by regarding higher rank symmetry as an emergent phenomenon, the RG analysis presented in this paper holds alternative promise for realizing higher rank symmetry and higher moment conservation in experimentally achievable systems.

The coupling of excitons with atomic vibrations plays a pivotal role on the nonequilibrium optical properties of layered semiconductors. However, how exciton-phonon coupling manifests in the time and energy domains is still an open debate between experiment and theory. By means of time-resolved broadband optical reflectivity combined with ab initio calculations of a bismuth tri-iodide single crystal, we set the spectral fingerprints for the optical detection of exciton-phonon coupling in layered semiconductors. Our joint experimental and theoretical effort allows us to unravel the impact of exciton-phonon coupling by microscopically relating the photoinduced coherent energy modulation of the excitonic resonance to coherent optical phonons. This enables us to track the extent of the photoinduced atomic displacement in real space. Our findings represent a step forward on the road to coherent manipulation of the excitonic properties on ultrafast timescales.

Nuclear spins in certain solids couple weakly to their environment, making them attractive candidates for quantum information processing and inertial sensing. When coupled to the spin of an optically active electron, nuclear spins can be rapidly polarized, controlled, and read via lasers and radio-frequency (rf) fields. Possessing typical coherence times of several milliseconds at room temperature, nuclear spins hosted by a nitrogen-vacancy center in diamond are thus intriguing systems to observe how classical physical rotation at quantum timescales affects a quantum system. In this work, we demonstrate optical nuclear-spin polarization and rapid quantum control of nuclear spins in a diamond physically rotating at $1\mathrm{kHz}$, faster than the nuclear-spin coherence time. Free from the need to maintain strict field alignment, we are able to measure and control nuclear spins in the presence of a large, time-varying magnetic field that makes an angle of more than ${100}^{\circ }$ to the nitrogen-lattice vacancy axis. The field induces spin mixing between the electron and nuclear states of the qubits, decoupling them from oscillating rf fields. We are able to demonstrate that coherent spin state control is possible at any point of the rotation. We combine continuous dynamical decoupling with feed-forward control to eliminate decoherence induced by imperfect mechanical rotation. Our work liberates a previously inaccessible degree of freedom of the NV nuclear spin, unlocking new approaches to quantum control and rotation sensing.

Moiré superpotentials in two-dimensional materials allow unprecedented control of the ratio between kinetic and interaction energy. By this they pave the way to study a wide variety of strongly correlated physics under a new light. In particular, the transition-metal dichalcogenides (TMDs) are promising candidate “quantum simulators” of the Hubbard model on a triangular lattice. Indeed, Mott and generalized Wigner crystals have been observed in such devices. Here we theoretically propose to extend this model into the multiorbital regime by focusing on electron-doped systems at filling higher than 2. As opposed to hole bands, the electronic bands in TMD materials include two, nearly degenerate species, which can be viewed as two orbitals with different effective mass and binding energy. Using realistic band-structure parameters and a slave-rotor mean-field theory, we find that an orbitally selective Mott (OSM) phase can be stabilized over a wide range of fillings, where one band is locked in a commensurate Mott state, while the other remains itinerant with variable density. This scenario thus realizes the basic ingredients in the Kondo lattice model: a periodic lattice of localized magnetic moments interacting with metallic states. We also discuss possible experimental signatures of the OSM state.

Near equilibrium, Green-Kubo relations provide microscopic expressions for macroscopic transport coefficients in terms of equilibrium correlation functions. At their core, they are based on the intimate relationship between response and fluctuations as embodied by the equilibrium fluctuation-dissipation theorem, a connection generically broken far from equilibrium. In this paper, we identify a class of perturbations whose response around far-from-equilibrium steady states is linked to steady-state correlation functions via an equilibrium-like fluctuation-response equality. We then utilize this prediction to substantiate linearized hydrodynamic transport equations that describe how spatial inhomogeneities in macroscopic nonequilibrium systems relax. As a consequence, we derive nonequilibrium Green-Kubo relations for the transport coefficients of two types of hydrodynamic variables: local conserved densities and broken-symmetry modes. A by-product of this work is to provide a theoretical foundation for the validity of Onsager's regression hypothesis around nonequilibrium steady states. Our predictions are analytically and numerically corroborated for two model systems: density diffusion in a fluid of soft, spherical active Brownian particles and phase diffusion in the noisy Kuramoto model on a square lattice.

We report noninvasive detection of spin coherence in a collection of Raman-driven cold atoms using dispersive Faraday rotation fluctuation measurements, which opens possibilities of probing spin correlations in quantum gases and other similar systems. We demonstrate five orders of magnitude enhancement of the measured signal strength as compared to traditional spin noise spectroscopy with thermal atoms in equilibrium. Our observations are in good agreement with the comprehensive theoretical modeling of the driven atoms at various temperatures. The extracted spin relaxation rate of cold rubidium atoms with atom number density $\sim 10{}^9/{\mathrm{cm}}^3$ is of the order of $3\times 10{}^3{\mathrm{s}}^{-1}$ at 150 $\mu \mathrm{K}$, two orders of magnitude less than $3\times 10{}^5{\mathrm{s}}^{-1}$ of that of a thermal atomic vapor with atom number density $\sim 10{}^{12}/{\mathrm{cm}}^3$ at 373 K.

Spin-charge interconversion is a very active area of research in spintronics. Yet, the complex behavior of some of the most promising systems such as ${\mathrm{SrTiO}}_3$ (STO) interfaces is not fully understood. Here, on the basis of a 6-band $\mathit{k}.\mathit{p}$ method combined with spin-resolved scattering theory, we give a theoretical demonstration of transverse spin-charge interconversion physics in STO Rashba interfaces. Calculations involve injection of spin current from a ferromagnetic contact by resonant tunneling into the native Rashba-split resonant levels of the STO triangular quantum well. We compute an asymmetric tunneling electronic transmission yielding a transverse charge current flowing in plane, with a dependence with gate voltage in a very good agreement with existing experimental data.

A dynamic mean-field theory for spin ensembles (spinDMFT) at infinite temperatures on arbitrary lattices is established. The approach is introduced for an isotropic Heisenberg model with $S=\frac{1}{2}$ and external field. For large coordination numbers, it is shown that the effect of the environment of each spin is captured by a classical time-dependent random mean field which is normally distributed. Expectation values are calculated by averaging over these mean fields, i.e., by a path integral over the normal distributions. A self-consistency condition is derived by linking the moments defining the normal distributions to spin autocorrelations. In this framework, we explicitly show how the rotating-wave approximation becomes a valid description for increasing magnetic field. We also demonstrate that the approach can easily be extended. Exemplarily, we employ it to reach a quantitative understanding of a dense ensemble of spins with dipolar interaction which are distributed randomly on a plane including static Gaussian noise as well.

Probabilistic cellular automata (CA) provide a classic framework for studying nonequilibrium statistical physics on lattices. A notable example is the Domany-Kinzel CA, which has been used to investigate the process of directed percolation and the critical dynamics of the nonequilibrium phase transition between absorbing and percolating phases. In this work, we construct a nonunitary quantum CA that generalizes the Domany-Kinzel CA and study the resulting dynamical evolution using numerical simulations using the tensor network infinite time-evolving block decimation (iTEBD) algorithm. We demonstrate that the system undergoes the absorbing/percolating phase transition and that the addition of the Hamiltonian generates coherences, which are a distinct feature of quantum dynamics. A proposal for the implementation of the model with Rydberg array is put forward, which does not require local addressing of individual sites.

How to accurately characterize the modulus of living cells at the whole-cell level with a well-defined measurement geometry and precise mathematical modeling of viscoelastic relaxation is an ongoing challenge in biophysics and mechanobiology. Here, we report combined atomic-force-microscopy (AFM) measurements of stress relaxation and indentation force for 10 cell types ranging from epithelial, muscle, and neuronal cells to blood and stem cells, from which we obtain a unified quantitative description of the compressive modulus $E\left(t\right)$ of individual living cells. The cell modulus $E\left(t\right)$ is found to have an initial exponential decay at short times $t$ followed by a long-time power-law decay together with a persistent modulus. The three components of $E\left(t\right)$ at different timescales thus provide a digital spectrum of mechanical readouts that are closely linked to the hierarchical structure and active stress of living cells. This work provides a reliable experimental framework that can be utilized to characterize the mechanical state of living cells and investigate their physiological functions and diseased states.