We use vortex photon fields with orbital and spin angular momentum to probe chiral fluctuations within liquid crystals. In the regime of iridescence with a well-defined pitch length of chirality, we find low energy Raman scattering that can be decomposed into helical and chiral components depending on the scattering vector and the topological charge of the incident photon field. Based on the observation of an anomalous dispersion we attribute quasielastic scattering to a transfer of angular momenta to rotonlike quasiparticles. The latter are due to a competition of short-range repulsive and long-range dipolar interactions. Our approach using a transfer of orbital angular momentum opens up an avenue for the advanced characterization of chiral and optically active devices and materials.

The competition between the Kondo correlation and superconductivity in quantum-dot Josephson junctions (QDJJs) has been known to drive a quantum phase transition between 0 and $\pi$ junctions. Theoretical studies so far have predicted that under strong Coulomb correlations the $0\text{−}\pi$ transition should go through intermediate states, $0^{\prime }$ and ${\pi }^{\prime }$ phases. By combining a nonperturbative numerical method and the resistively shunted junction model, we investigated the magnetic-field-driven phase transition of the QDJJs in the Kondo regime and found that the low-field magnetotransport exhibits a unique feature which can be used to distinguish the intermediate phases. In particular, the magnetic-field driven ${\pi }^{\prime }\text{−}\pi$ transition is found to lead to the enhancement of the supercurrent which is strongly related to the Kondo effect.

Amorphous solids such as coffee foam, toothpaste, or mayonnaise display a transient creep flow when a stress $\mathrm{\Sigma }$ is suddenly imposed. The associated strain rate is commonly found to decay in time as $\dot{\gamma }\sim t^{-\nu }$, followed either by arrest or by a sudden fluidization. Various empirical laws have been suggested for the creep exponent $\nu$ and fluidization time ${\tau }_f$ in experimental and numerical studies. Here, we postulate that plastic flow is governed by the difference between $\mathrm{\Sigma }$ and the transient yield stress ${\mathrm{\Sigma }}_t(\gamma )$ that characterizes the stability of configurations visited by the system at strain $\gamma$. Assuming the analyticity of ${\mathrm{\Sigma }}_t(\gamma )$ allows us to predict $\nu$ and asymptotic behaviors of ${\tau }_f$ in terms of properties of stationary flows. We test successfully our predictions using elastoplastic models and published experimental results.

We realize a turbulent cascade of wave excitations in a homogeneous 2D Bose gas and probe on all relevant time and length scales how it builds up from small to large momenta, until the system reaches a steady state with matching energy injection and dissipation. This all-scales view directly reveals the two theoretically expected cornerstones of turbulence formation—the emergence of statistical momentum-space isotropy under anisotropic forcing and the spatiotemporal scaling of the momentum distribution at times before any energy is dissipated.

The application of an external 26 Tesla axial magnetic field to a ${\mathrm{D}}_2$ gas-filled capsule indirectly driven on the National Ignition Facility is observed to increase the ion temperature by 40% and the neutron yield by a factor of 3.2 in a hot spot with areal density and temperature approaching what is required for fusion ignition [1]. The improvements are determined from energy spectral measurements of the 2.45 MeV neutrons from the $\mathrm{D}(d,n){}^3\mathrm{He}$ reaction, and the compressed central core $B$ field is estimated to be $\sim 4.9\mathrm{k}\mathrm{T}$ using the 14.1 MeV secondary neutrons from the $\mathrm{D}(\mathrm{T},n){}^4\mathrm{He}$ reactions. The experiments use a 30 kV pulsed-power system to deliver a $\sim 3\mu \mathrm{s}$ current pulse to a solenoidal coil wrapped around a novel high-electrical-resistivity ${\mathrm{AuTa}}_4$ hohlraum. Radiation magnetohydrodynamic simulations are consistent with the experiment.

In quantum logic spectroscopy (QLS), one species of trapped ion is used as a sensor to detect the state of an otherwise inaccessible ion species. This extends precision measurements to a broader class of atomic and molecular systems for applications like atomic clocks and tests of fundamental physics. Here, we develop a new technique based on a Schrödinger cat interferometer to address the problem of scaling QLS to larger ion numbers. We demonstrate the basic features of this method using various combinations of ${}^{25}{\mathrm{Mg}}^{+}$ logic ions and ${}^{27}{\mathrm{Al}}^{+}$ spectroscopy ions. We observe higher detection efficiency by increasing the number of ${}^{25}{\mathrm{Mg}}^{+}$ ions. Applied to multiple ${}^{27}{\mathrm{Al}}^{+}$, this method will improve the stability of high-accuracy optical clocks and could enable Heisenberg-limited QLS.

Combinatorial problems arising in puzzles, origami, and (meta)material design have rare sets of solutions, which define complex and sharply delineated boundaries in configuration space. These boundaries are difficult to capture with conventional statistical and numerical methods. Here we show that convolutional neural networks can learn to recognize these boundaries for combinatorial mechanical metamaterials, down to finest detail, despite using heavily undersampled training sets, and can successfully generalize. This suggests that the network infers the underlying combinatorial rules from the sparse training set, opening up new possibilities for complex design of (meta)materials.

Impulsive supernova feedback and nonstandard dark matter models, such as self-interacting dark matter (SIDM), are the two main contenders for the role of the dominant core formation mechanism at the dwarf galaxy scale. Here we show that the impulsive supernova cycles that follow episodes of bursty star formation leave distinct features in the distribution function of stars: groups of stars with similar ages and metallicities develop overdense shells in phase space. If cores are formed through supernova feedback, we predict the presence of such features in star-forming dwarf galaxies with cored host halos. Their systematic absence would favor alternative dark matter models, such as SIDM, as the dominant core formation mechanism.

In a recent work [A. Deger et al., Phys. Rev. Lett. 129, 160601 (2022).] we have shown that kinetic constraints can completely arrest many-body chaos in the dynamics of a classical, deterministic, translationally invariant spin system with the strength of the constraint driving a dynamical phase transition. Using extensive numerical simulations and scaling analyses we demonstrate here that this constraint-induced phase transition lies in the directed percolation universality class in both one and two spatial dimensions.

In this Letter, employing the generalized off-shell free energy, we treat black hole solutions as defects in the thermodynamic parameter space. The results show that the positive and negative winding numbers corresponding to the defects indicate the local thermodynamical stable and unstable black hole solutions, respectively. The topological number defined as the sum of the winding numbers for all the black hole branches at an arbitrary given temperature is found to be a universal number independent of the black hole parameters. Moreover, this topological number only depends on the thermodynamic asymptotic behaviors of the black hole temperature at small and large black hole limits. Different black hole systems are characterized by three classes via this topological number. This number could help us in better understanding the black hole thermodynamics and, further, shed new light on the fundamental nature of quantum gravity.

We study the effect of doping on the electron-phonon interaction and on the phonon frequencies in doped semiconductors, taking into account the screening in the presence of free carriers at finite temperature. We study the impact of screening on the Fröhlich-like vertex and on the long-range components of the dynamical matrix, going beyond the state-of-the-art description for undoped crystals, thanks to the development of a computational method based on maximally localized Wannier functions. We apply our approach to cubic silicon carbide, where in the presence of doping the Fröhlich coupling and the longitudinal-transverse phonon splitting are strongly reduced, thereby influencing observable properties such as the electronic lifetime.

Whispering gallery modes (WGMs) in circularly symmetric optical microresonators exhibit integer quantized angular momentum numbers due to the boundary condition imposed by the geometry. Here, we show that incorporating a photonic crystal pattern in an integrated microring can result in WGMs with fractional optical angular momentum. By choosing the photonic crystal periodicity to open a photonic band gap with a band-edge momentum lying between that of two WGMs of the unperturbed ring, we observe hybridized WGMs with half-integer quantized angular momentum numbers ($m\in \mathbb{Z}+1/2$). Moreover, we show that these modes with fractional angular momenta exhibit high optical quality factors with good cavity-waveguide coupling and an order of magnitude reduced group velocity. Additionally, by introducing multiple artificial defects, multiple modes can be localized to small volumes within the ring, while the relative orientation of the delocalized band-edge states can be well controlled. Our Letter unveils the renormalization of WGMs by the photonic crystal, demonstrating novel fractional angular momentum states and nontrivial multimode orientation control arising from continuous rotational symmetry breaking. The findings are expected to be useful for sensing and metrology, nonlinear optics, and cavity quantum electrodynamics.

We show that incompressible polar active fluids can exhibit an ordered, coherently moving phase even in the presence of quenched disorder in two dimensions. Unlike such active fluids with annealed disorder (i.e., time-dependent random white noise) only, which behave like equilibrium ferromagnets with long-range interactions, this robustness against quenched disorder is a fundamentally nonequilibrium phenomenon. The ordered state belongs to a new universality class, whose scaling laws we calculate using three different renormalization group schemes, which all give scaling exponents within 0.02 of each other, indicating that our results are quite accurate. Our predictions can be quantitatively tested in readily available artificial active systems and imply that biological systems such as cell layers can move coherently in vivo, where disorder is inevitable.

Fully general-relativistic binary-neutron-star (BNS) merger simulations with quark-hadron crossover (QHC) equations of state (EOS) are studied for the first time. In contrast to EOS with purely hadronic matter or with a first-order quark-hadron phase transition (1PT), in the transition region QHC EOS show a peak in sound speed and thus a stiffening. We study the effects of such stiffening in the merger and postmerger gravitational (GW) signals. Through simulations in the binary-mass range $2.5<M/M_{\odot }<2.75$, characteristic differences due to different EOS appear in the frequency of the main peak of the postmerger GW spectrum ($f_2$), extracted through Bayesian inference. In particular, we found that (i) for lower-mass binaries, since the maximum baryon number density ($n_{\max }$) after the merger stays below 3–4 times the nuclear-matter density ($n_0$), the characteristic stiffening of the QHC models in that density range results in a lower $f_2$ than that computed for the underlying hadronic EOS and thus also than that for EOS with a 1PT; (ii) for higher-mass binaries, where $n_{\max }$ may exceed $4–5n_0$ depending on the EOS model, whether $f_2$ in QHC models is higher or lower than that in the underlying hadronic model depends on the height of the sound-speed peak. Comparing the values of $f_2$ for different EOS and BNS masses gives important clues on how to discriminate different types of quark dynamics in the high-density end of EOS and is relevant to future kilohertz GW observations with third-generation GW detectors.

We present the first experimental evidence for the multifractality of a transport property at a topological phase transition. In particular, we show that conductance fluctuations display multifractality at the integer quantum Hall plateau-to-plateau transitions in high-mobility mesoscopic graphene devices. The multifractality gets rapidly suppressed as the chemical potential moves away from these critical points. Our combination of experimental study and multifractal analysis provides a novel method for probing the criticality of wave functions at phase transitions in mesoscopic systems, and quantum criticality in several condensed-matter systems.

Understanding and predicting lattice dynamics in strongly anharmonic crystals is one of the long-standing challenges in condensed matter physics. Here, we propose a first-principles method that gives accurate quasiparticle (QP) peaks of the phonon spectrum with strong anharmonic broadening. On top of the conventional first-order self-consistent phonon (SC1) dynamical matrix, the proposed method incorporates frequency renormalization effects by the bubble self-energy within the QP approximation. We apply the developed methodology to the strongly anharmonic $\alpha \text{−}{\text{CsPbBr}}_3$ that displays phonon instability within the harmonic approximation in the whole Brillouin zone. While the SC1 theory significantly underestimates the cubic-to-tetragonal phase transition temperature ($T_c$) by more than 50%, we show that our approach yields $T_c=404–423\mathrm{K}$, in excellent agreement with the experimental value of 403 K. We also demonstrate that an accurate determination of QP peaks is paramount for quantitative prediction and elucidation of the phonon linewidth.

Floquet engineering offers a compelling approach for designing the time evolution of periodically driven systems. We implement a periodic atom-light coupling to realize Floquet atom optics on the strontium ${{}^{1}S}_0-{}^3{P}_1$ transition. These atom optics reach pulse efficiencies above 99.4% over a wide range of frequency offsets between light and atomic resonance, even under strong driving where this detuning is on the order of the Rabi frequency. Moreover, we use Floquet atom optics to compensate for differential Doppler shifts in large momentum transfer atom interferometers and achieve state-of-the-art momentum separation in excess of $400\hslash k$. This technique can be applied to any two-level system at arbitrary coupling strength, with broad application in coherent quantum control.

We demonstrate a light-pulse atom interferometer based on the diffraction of free-falling atoms by a picosecond frequency-comb laser. More specifically, we coherently split and recombine wave packets of cold ${}^{87}\mathrm{Rb}$ atoms by driving stimulated Raman transitions between the $|5s{}^2{S}_{1/2},F=1⟩$ and $|5s{}^2{S}_{1/2},F=2⟩$ hyperfine states, using two trains of picosecond pulses in a counterpropagating geometry. We study the impact of the pulses’ length as well as the interrogation time onto the contrast of the atom interferometer. Our experimental data are well reproduced by a numerical simulation based on an effective coupling that depends on the overlap between the pulses and the atomic cloud. These results pave the way for extending light-pulse interferometry to transitions in other spectral regions and therefore to other species, for new possibilities in metrology, sensing of gravito-inertial effects, and tests of fundamental physics.

Tin-vacancy centers in diamond are promising spin-photon interfaces owing to their high quantum efficiency, large Debye-Waller factor, and compatibility with photonic nanostructuring. Benchmarking their single-photon indistinguishability is a key challenge for future applications. Here, we report the generation of single photons with ${99.7}_{-2.5}^{+0.3}\%$ purity and 63(9)% indistinguishability from a resonantly excited tin-vacancy center in a single-mode waveguide. We obtain quantum control of the optical transition with 1.71(1)-ns-long $\pi$ pulses of 77.1(8)% fidelity and show it is spectrally stable over 100 ms. A modest Purcell enhancement factor of 12 would enhance the indistinguishability to 95%.

Doubts have been raised on the representation of chiral spin liquids exhibiting topological order in terms of projected entangled pair states (PEPSs). Here, starting from a simple spin-$1/2$ chiral frustrated Heisenberg model, we show that a faithful representation of the chiral spin liquid phase is in fact possible in terms of a generic PEPS upon variational optimization. We find a perfectly chiral gapless edge mode and a rapid decay of correlation functions at short distances consistent with a bulk gap, concomitant with a gossamer long-range tail originating from a PEPS bulk-edge correspondence. For increasing bond dimension, (i) the rapid decrease of spurious features—SU(2) symmetry breaking and long-range tails in correlations—together with (ii) a faster convergence of the ground state energy as compared to state-of-the-art cylinder matrix-product state simulations involving far more variational parameters, prove the fundamental relevance of the PEPS ansatz for simulating systems with chiral topological order.