We present a coherent optical method for wavelength-resolution imaging of moving objects hidden within thick randomly scattering media. Spatial speckle intensity correlations as a function of object position are shown to provide access to the spatially dependent dielectric constant of the moving object. This speckle correlation imaging method yields field-based information previously inaccessible in heavily scattering environments. Proof of concept experimental results show excellent agreement with the theory. This new imaging approach will be valuable in high resolution imaging in tissue and other scattering environments where natural motion occurs or the object position can be controlled.

To control the efficiency of photoinduced charge-order melting in perovskite manganites, we performed femtosecond pump-probe spectroscopy using double-pulse excitation on ${\mathrm{Pr}}_{0.6}{\mathrm{Ca}}_{0.4}{\mathrm{MnO}}_3$. The results revealed that the transfer of the spectral weight from the near-infrared to infrared region by the second pump pulse is considerably enhanced by the first pump pulse and that the suppression of crystal anisotropy, that is, the decrease of long-range lattice deformations due to the charge order by the first pump pulse is a key factor to enhance the charge-order melting. This double-pulse excitation method can be applied to various photoinduced transitions in complex materials with electronic and structural instabilities.

We study the effects of Coulomb interaction between 2D Weyl fermions with anisotropic dispersion which displays relativistic dynamics along one direction and nonrelativistic dynamics along the other. Such a dispersion can be realized in phosphorene under electric field or strain, in ${\mathrm{TiO}}_2/{\mathrm{VO}}_2$ superlattices, and, more generally, at the quantum critical point between a nodal semimetal and an insulator in systems with a chiral symmetry. Using the one-loop renormalization group approach in combination with the large-$N$ expansion, we find that the system displays interaction-driven non-Fermi liquid behavior in a wide range of intermediate frequencies and marginal Fermi liquid behavior at the smallest frequencies. In the non-Fermi liquid regime, the quasiparticle residue $Z$ at energy $E$ scales as $Z\propto E^a$ with $a>0$, and the parameters of the fermionic dispersion acquire anomalous dimensions. In the marginal Fermi-liquid regime, $Z\propto (|\log E|{)}^{-b}$ with universal $b=3/2$.

We report the evolution of superconductivity in an FeSe thin flake with systematically regulated carrier concentrations by the liquid-gating technique. With electron doping tuned by the gate voltage, high-temperature superconductivity with an onset at 48 K can be achieved in an FeSe thin flake with $T_c$ less than 10 K. This is the first time such high temperature superconductivity in FeSe is achieved without either an epitaxial interface or external pressure, and it definitely proves that the simple electron-doping process is able to induce high-temperature superconductivity with $T_c^{\text{onset}}$ as high as 48 K in bulk FeSe. Intriguingly, our data also indicate that the superconductivity is suddenly changed from a low-$T_c$ phase to a high-$T_c$ phase with a Lifshitz transition at a certain carrier concentration. These results help to build a unified picture to understand the high-temperature superconductivity among all FeSe-derived superconductors and shed light on the further pursuit of a higher $T_c$ in these materials.

The current density ${\mathit{j}}^{\mathbf{B}}$ induced in a clean metal by a slowly-varying magnetic field $\mathbf{B}$ is formulated as the low-frequency limit of natural optical activity, or natural gyrotropy. Working with a multiband Pauli Hamiltonian, we obtain from the Kubo formula a simple expression for ${\alpha }_{ij}^{\mathrm{GME}}=j_i^{\mathbf{B}}/B_j$ in terms of the intrinsic magnetic moment (orbital plus spin) of the Bloch electrons on the Fermi surface. An alternate semiclassical derivation provides an intuitive picture of the effect, and takes into account the influence of scattering processes in dirty metals. This “gyrotropic magnetic effect” is fundamentally different from the chiral magnetic effect driven by the chiral anomaly and governed by the Berry curvature on the Fermi surface, and the two effects are compared for a minimal model of a Weyl semimetal. Like the Berry curvature, the intrinsic magnetic moment should be regarded as a basic ingredient in the Fermi-liquid description of transport in broken-symmetry metals.

We show theoretically that near a fluid-fluid interface a single active colloidal particle generating, e.g., chemicals or a temperature gradient experiences an effective force of hydrodynamic origin. This force is due to the fluid flow driven by Marangoni stresses induced by the activity of the particle; it decays very slowly with the distance from the interface, and can be attractive or repulsive depending on how the activity modifies the surface tension. We show that, for typical systems, this interaction can dominate the dynamics of the particle as compared to Brownian motion, dispersion forces, or self-phoretic effects. In the attractive case, the interaction promotes the self-assembly of particles into a crystal-like monolayer at the interface.

Hypergraph states form a family of multiparticle quantum states that generalizes the well-known concept of Greenberger-Horne-Zeilinger states, cluster states, and more broadly graph states. We study the nonlocal properties of quantum hypergraph states. We demonstrate that the correlations in hypergraph states can be used to derive various types of nonlocality proofs, including Hardy-type arguments and Bell inequalities for genuine multiparticle nonlocality. Moreover, we show that hypergraph states allow for an exponentially increasing violation of local realism which is robust against loss of particles. Our results suggest that certain classes of hypergraph states are novel resources for quantum metrology and measurement-based quantum computation.

We introduce and study the task of assisted coherence distillation. This task arises naturally in bipartite systems where both parties work together to generate the maximal possible coherence on one of the subsystems. Only incoherent operations are allowed on the target system, while general local quantum operations are permitted on the other; this is an operational paradigm that we call local quantum-incoherent operations and classical communication. We show that the asymptotic rate of assisted coherence distillation for pure states is equal to the coherence of assistance, an analog of the entanglement of assistance, whose properties we characterize. Our findings imply a novel interpretation of the von Neumann entropy: it quantifies the maximum amount of extra quantum coherence a system can gain when receiving assistance from a collaborative party. Our results are generalized to coherence localization in a multipartite setting and possible applications are discussed.

We identify a new universality class in one-dimensional driven open quantum systems with a dark state. Salient features are the persistence of both the microscopic nonequilibrium conditions as well as the quantum coherence of dynamics close to criticality. This provides a nonequilibrium analogue of quantum criticality, and is sharply distinct from more generic driven systems, where both effective thermalization as well as asymptotic decoherence ensue, paralleling classical dynamical criticality. We quantify universality by computing the full set of independent critical exponents within a functional renormalization group approach.

Two different nuclear-medium effects are isolated using a low three-momentum transfer subsample of neutrino-carbon scattering data from the MINERvA neutrino experiment. The observed hadronic energy in charged-current ${\nu }_{\mu }$ interactions is combined with muon kinematics to permit separation of the quasielastic and $\mathrm{\Delta }(1232)$ resonance processes. First, we observe a small cross section at very low energy transfer that matches the expected screening effect of long-range nucleon correlations. Second, additions to the event rate in the kinematic region between the quasielastic and $\mathrm{\Delta }$ resonance processes are needed to describe the data. The data in this kinematic region also have an enhanced population of multiproton final states. Contributions predicted for scattering from a nucleon pair have both properties; the model tested in this analysis is a significant improvement but does not fully describe the data. We present the results as a double-differential cross section to enable further investigation of nuclear models. Improved description of the effects of the nuclear environment are required by current and future neutrino oscillation experiments.

The atomic mass relations among the mass triplet ${}^{96}\mathrm{Zr}$, ${}^{96}\mathrm{Nb}$, and ${}^{96}\mathrm{Mo}$ have been determined by means of high-precision mass measurements using the JYFLTRAP mass spectrometer at the IGISOL facility of the University of Jyväskylä. We report $Q$ values for the ${}^{96}\mathrm{Zr}$ single and double $\beta$ decays to ${}^{96}\mathrm{Nb}$ and ${}^{96}\mathrm{Mo}$, as well as the $Q$ value for the ${}^{96}\mathrm{Nb}$ single $\beta$ decay to ${}^{96}\mathrm{Mo}$, which are $Q_{\beta }({}^{96}\mathrm{Zr})=163.96(13)$, $Q_{\beta \beta }({}^{96}\mathrm{Zr})=3356.097(86)$, and $Q_{\beta }({}^{96}\mathrm{Nb})=3192.05(16)\mathrm{keV}$. Of special importance is the ${}^{96}\mathrm{Zr}$ single $\beta$-decay $Q$ value, which has never been determined directly. The single $\beta$ decay, whose main branch is fourfold unique forbidden, is an alternative decay path to the ${}^{96}\mathrm{Zr}$ $\beta \beta$ decay, and its observation can provide one of the most direct tests of the neutrinoless $\beta \beta$-decay nuclear-matrix-element calculations, as these can be simultaneously performed for both decay paths with no further assumptions. The theoretical single $\beta$-decay rate has been re-evaluated using a shell-model approach, which indicates a ${}^{96}\mathrm{Zr}$ single $\beta$-decay lifetime within reach of an experimental verification. The uniqueness of the decay also makes such an experiment interesting for an investigation into the origin of the quenching of the axial-vector coupling constant $g_A$.

We demonstrate that there is an optimal forcing length scale for low Prandtl number dynamo flows that can significantly reduce the required energy injection rate. The investigation is based on simulations of the induction equation in a periodic box of size $2\pi L$. The flows considered are the laminar and turbulent $ABC$ flows forced at different forcing wave numbers $k_f$, where the turbulent case is simulated using a subgrid turbulence model. At the smallest allowed forcing wave number $k_f=k_{\min }=1/L$ the laminar critical magnetic Reynolds number $R{m}_c^{\mathrm{lam}}$ is more than an order of magnitude smaller than the turbulent critical magnetic Reynolds number ${Rm}_c^{\mathrm{turb}}$ due to the hindering effect of turbulent fluctuations. We show that this hindering effect is almost suppressed when the forcing wave number $k_f$ is increased above an optimum wave number $k_{f}L\simeq 4$ for which ${Rm}_c^{\mathrm{turb}}$ is minimum. At this optimal wave number, ${Rm}_c^{\mathrm{turb}}$ is smaller by more than a factor of 10 than the case forced in $k_f=1$. This leads to a reduction of the energy injection rate by 3 orders of magnitude when compared to the case where the system is forced at the largest scales and thus provides a new strategy for the design of a fully turbulent experimental dynamo.

We present a theoretical model that allows a fast and accurate evaluation of ionic transport properties of realistic plasmas spanning from warm and dense to hot and dilute conditions, including mixtures. This is achieved by combining a recent kinetic theory based on effective interaction potentials with a model for the equilibrium radial density distribution based on an average atom model and the integral equations theory of fluids. The model should find broad use in applications where nonideal plasma conditions are traversed, including inertial confinement fusion, compact astrophysical objects, solar and extrasolar planets, and numerous present-day high energy density laboratory experiments.

In hohlraums for inertial confinement fusion (ICF) implosions on the National Ignition Facility, suprathermal hot electrons, generated by laser plasma instabilities early in the laser pulse (“picket”) while blowing down the laser entrance hole (LEH) windows, can preheat the capsule fuel. Hard x-ray imaging of a Bi capsule surrogate and of the hohlraum emissions, in conjunction with the measurement of time-resolved bremsstrahlung spectra, allows us to uncover for the first time the directionality of these hot electrons and infer the capsule preheat. Data and Monte Carlo calculations indicate that for most experiments the hot electrons are emitted nearly isotropically from the LEH. However, we have found cases where a significant fraction of the generated electrons are emitted in a collimated beam directly towards the capsule poles, where their local energy deposition is up to $10\times$ higher than the average preheat value and acceptable levels for ICF implosions. The observed “beaming” is consistent with a recently unveiled multibeam stimulated Raman scattering model [P. Michel et al., Phys. Rev. Lett. 115, 055003 (2015)], where laser beams in a cone drive a common plasma wave on axis. Finally, we demonstrate that we can control the amount of generated hot electrons by changing the laser pulse shape and hohlraum plasma.