By manipulating the momenta of ultracold atoms, researchers demonstrate a quantum walk—a potential ingredient for quantum search algorithms.

[Phys. Rev. Lett. 121, 070402] Published Thu Aug 16, 2018

]]>Cavity QED is a promising avenue for the deterministic generation of entangled and spin-squeezed states for quantum metrology. One archetypal scheme generates squeezing via collective one-axis twisting interactions. However, we show that in implementations using optical transitions in long-lived ato...

[Phys. Rev. Lett. 121, 070403] Published Thu Aug 16, 2018

]]>Coherent control of reactants remains a long-standing challenge in quantum chemistry. In particular, we have studied laser-induced molecular formation (photoassociation) in a Raman-dressed spin-orbit-coupled ${}^{87}\mathrm{Rb}$ Bose-Einstein condensate, whose spin quantum state is a superposition of multiple bare ...

[Phys. Rev. Lett. 121, 073202] Published Thu Aug 16, 2018

]]>Light carries momentum which induces on atoms a recoil for each photon absorbed. In vacuum, for a monochromatic beam of frequency $\nu $, the global momentum per photon is bounded by general principles and is smaller than $h\nu /c$ leading to a limit on the recoil. However, locally this limit can be broken. I...

[Phys. Rev. Lett. 121, 073603] Published Thu Aug 16, 2018

]]>We report on the experimental realization of a uniform synthetic magnetic flux and the observation of Aharonov-Bohm cages in photonic lattices. Considering a rhombic array of optical waveguides, we engineer modulation-assisted tunneling processes that effectively produce nonzero magnetic flux per pl...

[Phys. Rev. Lett. 121, 075502] Published Thu Aug 16, 2018

]]>We identify sufficient conditions on the structure of the interaction Hamiltonian between a two-level quantum system and a thermal bath that, without any external drive or coherent measurement, guarantee the generation of steady-state coherences (SSC). The SSC obtained this way, remarkably, turn out...

[Phys. Rev. Lett. 121, 070401] Published Wed Aug 15, 2018

]]>We consider the speed limit for classical stochastic Markov processes with and without the local detailed balance condition. We find that, for both cases, a trade-off inequality exists between the speed of the state transformation and the entropy production. The dynamical activity is related to a ti...

[Phys. Rev. Lett. 121, 070601] Published Wed Aug 15, 2018

]]>Renormalization group analysis is applied to uncover several general features of quantum field theories with disorder, including the existence of a new critical exponent.

[Phys. Rev. Lett. 121, 071601] Published Wed Aug 15, 2018

]]>The leptonic decay of charged pions is investigated in the presence of background magnetic fields. In this situation, Lorentz symmetry is broken, and new fundamental decay constants need to be introduced, associated with the decay via the vector part of the electroweak current. We calculate the magn...

[Phys. Rev. Lett. 121, 072001] Published Wed Aug 15, 2018

]]>From samples of $pp$ collision data collected by the LHCb experiment at $\sqrt{s}=7$, 8 and 13 TeV, corresponding to integrated luminosities of 1.0, 2.0 and $1.5\text{\hspace{0.17em}}\text{\hspace{0.17em}}{\mathrm{fb}}^{-1}$, respectively, a peak in both the ${\mathrm{\Lambda}}_{b}^{0}{K}^{-}$ and ${\mathrm{\Xi}}_{b}^{0}{\pi}^{-}$ invariant mass spectra is observed. In the quark model, radially and orbitally excited ${\mathrm{\Xi}}_{b}^{-}$ res...

[Phys. Rev. Lett. 121, 072002] Published Wed Aug 15, 2018

]]>We present a general theory that enables the first nonempirical computation of molecular vibrational Zeeman effects as are detectable with magnetic vibrational circular dichroism spectroscopy (MVCD). In this method, the second derivatives of the molecular magnetic moment appear to be essential to de...

[Phys. Rev. Lett. 121, 073201] Published Wed Aug 15, 2018

]]>We propose an incident direction independent wave propagation generated by properly assembling different unidirectional destructive interferences (UDIs), which is a consequence of the appropriate match between synthetic magnetic fluxes and the incident wave vector. Single-direction lasing at spectra...

[Phys. Rev. Lett. 121, 073901] Published Wed Aug 15, 2018

]]>We present a new measurement of lattice disassembly times in femtosecond-laser-heated polycrystalline Au nanofoils. The results are compared with molecular dynamics simulations incorporating a highly optimized, embedded-atom-method interatomic potential. For absorbed energy densities of $0.9\u20134.3\text{\hspace{0.17em}}\text{\hspace{0.17em}}\mathrm{MJ}/\mathrm{...}$

[Phys. Rev. Lett. 121, 075002] Published Wed Aug 15, 2018

]]>We show that a wide class of layered superconductor-ferromagnet ($S/F$) hybrids demonstrates the emergence of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase well below the superconducting transition temperature. By decreasing the temperature, one can switch the system from uniform to the FFLO state...

[Phys. Rev. Lett. 121, 077002] Published Wed Aug 15, 2018

]]>Evolution of an overpopulated gas of magnons to a Bose-Einstein condensate and excitation of a magnon supercurrent, propelled by a phase gradient in the condensate wave function, can be observed at room temperature by means of the Brillouin light scattering spectroscopy in an yttrium iron garnet mat...

[Phys. Rev. Lett. 121, 077203] Published Wed Aug 15, 2018

]]>Using a new “all-electric” technique, researchers triple the energy gap between the two spin states of holes in a 2D quantum well.

[Phys. Rev. Lett. 121, 077701] Published Wed Aug 15, 2018

]]>We show that the evaporation of surfactant solutions confined in quasi-two-dimensional porous media creates micron-sized labyrinthine patterns composing the walls of a centimeter-sized maze. These walls are made of solid deposits formed during drying via a sequence of individual Haines jumps occurri...

[Phys. Rev. Lett. 121, 078002] Published Wed Aug 15, 2018

]]>The relativistic correction to the dissociation energy of ${\mathrm{H}}_{2}$, ${\mathrm{D}}_{2}$, and HD molecules has been accurately calculated without expansion in the small electron-nucleus mass ratio. The obtained results indicate the significance of nonadiabatic effects and resolve the discrepancy of theoretical predictions ...

[Phys. Rev. Lett. 121, 073001] Published Tue Aug 14, 2018

]]>The quantum coherence (QC) of two comoving atoms on a stationary trajectory is investigated. We develop a formalism to characterize the properties of atoms on a stationary trajectory. We give a criterion under which QC is frozen to a nonzero value. The frozen condition that vanishing super- or subra...

[Phys. Rev. Lett. 121, 073602] Published Tue Aug 14, 2018

]]>The controlled rotation of solid particles trapped in a liquid by an ultrasonic vortex beam is observed. Single polystyrene beads, or clusters, can be trapped against gravity while simultaneously rotated. The induced rotation of a single particle is compared to a torque balance model accounting for ...

[Phys. Rev. Lett. 121, 074301] Published Tue Aug 14, 2018

]]>A bifurcative step transition from low-density, high-temperature, attached divertor conditions to high-density, low-temperature, detached divertor conditions is experimentally observed in DIII-D tokamak plasmas as density is increased. The step transition is only observed in the high confinement mod...

[Phys. Rev. Lett. 121, 075001] Published Tue Aug 14, 2018

]]>Maps of solar wind velocities derived from satellite images of the Sun’s corona could help researchers improve solar wind models.

[Phys. Rev. Lett. 121, 075101] Published Tue Aug 14, 2018

]]>The decay of correlations in ionic fluids is a classical problem in soft matter physics that underpins applications ranging from controlling colloidal self-assembly to batteries and supercapacitors. The conventional wisdom, based on analyzing a solvent-free electrolyte model, suggests that all corre...

[Phys. Rev. Lett. 121, 075501] Published Tue Aug 14, 2018

]]>We develop a novel approach to the Anderson localization problem in a $d$-dimensional disordered sample of dimension $L\times {M}^{d-1}$. Attaching a perfect lead with the cross section ${M}^{d-1}$ to one side of the sample, we derive evolution equations for the scattering matrix and the Wigner-Smith time delay matrix as...

[Phys. Rev. Lett. 121, 076601] Published Tue Aug 14, 2018

]]>We investigate the magnetic field and temperature dependence of the single-electron spin lifetime in silicon quantum dots and find a lifetime of 2.8 ms at a temperature of 1.1 K. We develop a model based on spin-valley mixing and find that Johnson noise and two-phonon processes limit relaxation at l...

[Phys. Rev. Lett. 121, 076801] Published Tue Aug 14, 2018

]]>Periodically driven Kitaev chains show a rich phase diagram as the amplitude and frequency of the drive is varied, with topological phase transitions separating regions with different number of Majorana zero and $\pi $ modes. We explore whether the critical point separating different phases of the period...

[Phys. Rev. Lett. 121, 076802] Published Tue Aug 14, 2018

]]>We report the evolution of the electronic nematic susceptibility in FeSe via Raman scattering as a function of hydrostatic pressure up to 5.8 GPa where the superconducting transition temperature ${T}_{c}$ reaches its maximum. The critical nematic fluctuations observed at low pressure vanish above 1.6 GPa, ...

[Phys. Rev. Lett. 121, 077001] Published Tue Aug 14, 2018

]]>The nontriviality of quantum spin liquids (QSLs) typically manifests in the nonlocal observables that signify their existence; however, this fact actually casts a shadow on detecting QSLs with experimentally accessible probes. Here, we provide a solution by unbiasedly demonstrating a dynamical signa...

[Phys. Rev. Lett. 121, 077201] Published Tue Aug 14, 2018

]]>Based on large-scale quantum Monte Carlo simulations, we examine the dynamical spin structure factor of the Balents-Fisher-Girvin kagome lattice spin-$1/2$ model, which is known to harbor an extended ${Z}_{2}$ quantum spin liquid phase. We use a correlation-matrix sampling scheme combined with a stochastic a...

[Phys. Rev. Lett. 121, 077202] Published Tue Aug 14, 2018

]]>We demonstrate differential dynamic microscopy and particle tracking for the characterization of the spatiotemporal behavior of active Janus colloids in terms of the intermediate scattering function (ISF). We provide an analytical solution for the ISF of the paradigmatic active Brownian particle mod...

[Phys. Rev. Lett. 121, 078001] Published Tue Aug 14, 2018

]]>To estimate the time, many organisms, ranging from cyanobacteria to animals, employ a circadian clock which is based on a limit-cycle oscillator that can tick autonomously with a nearly 24 h period. Yet, a limit-cycle oscillator is not essential for knowing the time, as exemplified by bacteria that ...

[Phys. Rev. Lett. 121, 078101] Published Tue Aug 14, 2018

]]>[Phys. Rev. Lett. 121, 079901] Published Tue Aug 14, 2018

]]>We find that uniformly accelerated motion of a mirror yields excitation of a static two-level atom with simultaneous emission of a real photon. This occurs because of virtual transitions with probability governed by the Planck factor involving the photon frequency $\nu $ and the Unruh temperature. The re...

[Phys. Rev. Lett. 121, 071301] Published Mon Aug 13, 2018

]]>Researchers have entangled six modes of a laser cavity—a record number for such a device.

[Phys. Rev. Lett. 121, 073601] Published Mon Aug 13, 2018

]]>A hypothesis about the average phase-space distribution of resonance eigenfunctions in chaotic systems with escape through an opening is proposed. Eigenfunctions with decay rate $\gamma $ are described by a classical measure that (i) is conditionally invariant with classical decay rate $\gamma $ and (ii) is uniform...

[Phys. Rev. Lett. 121, 074101] Published Mon Aug 13, 2018

]]>Gamma-ray beams with a large angular momentum may affect astrophysical phenomena, which calls for appropriate earth-based experimental investigations. For this purpose, we investigate the generation of well-collimated $\gamma $-ray beams with a very large orbital angular momentum using nonlinear Compton sca...

[Phys. Rev. Lett. 121, 074801] Published Mon Aug 13, 2018

]]>Water exhibits numerous anomalous properties, many of which remain poorly understood. One of its intriguing behaviors is that it exhibits a temperature of maximum density (TMD) at $4\text{\hspace{0.17em}}\xb0\mathrm{C}$. We provide here new experimental evidence for hitherto unknown abrupt changes in proton transfer kinetics at the T...

[Phys. Rev. Lett. 121, 076001] Published Mon Aug 13, 2018

]]>A novel shape evolution in the Sn isotopes by the state-of-the-art application of the Monte Carlo shell model calculations is presented in a unified way for the ${}^{100\u2013138}\mathrm{Sn}$ isotopes. A large model space consisting of eight single-particle orbits for protons and neutrons is taken with the fixed Hamilto...

[Phys. Rev. Lett. 121, 062501] Published Fri Aug 10, 2018

]]>A new technique provides the first measurement of all six characteristics of a particle beam, which will help researchers improve beam quality.

[Phys. Rev. Lett. 121, 064804] Published Fri Aug 10, 2018

]]>We present a flexible scheme to realize non-Markovian dynamics of an electronic spin qubit, using a nitrogen-vacancy center in diamond where the inherent nitrogen spin serves as a regulator of the dynamics. By changing the population of the nitrogen spin, we show that we can smoothly tune the non-Ma...

[Phys. Rev. Lett. 121, 060401] Published Thu Aug 09, 2018

]]>The present study demonstrates that large electric fields progressively enhance the conductivity of ionic systems up to timescales corresponding to those on which their structural rearrangements take place. Yet, in many ionic materials, some regarded as candidates for electrical energy storage appli...

[Phys. Rev. Lett. 121, 064503] Published Thu Aug 09, 2018

]]>We establish a large deviation principle for the Kardar-Parisi-Zhang (KPZ) equation, providing precise control over the left tail of the height distribution for narrow wedge initial condition. Our analysis exploits an exact connection between the KPZ one-point distribution and the Airy point process...

[Phys. Rev. Lett. 121, 060201] Published Wed Aug 08, 2018

]]>Permutational quantum computing (PQC) [Quantum Inf. Comput., **10**, 470–497 (2010)] is a natural quantum computational model conjectured to capture nonclassical aspects of quantum computation. An argument backing this conjecture was the observation that there was no efficient classical algorithm for es...

[Phys. Rev. Lett. 121, 060505] Published Wed Aug 08, 2018

]]>It has been suggested that both quantum superpositions and nonlinear interactions are important resources for quantum metrology. However, to date the different roles that these two resources play in the precision enhancement are not well understood. Here, we experimentally demonstrate a Heisenberg-s...

[Phys. Rev. Lett. 121, 060506] Published Wed Aug 08, 2018

]]>If dark matter stems from the background of a very light gauge boson, this gauge boson could exert forces on test masses in gravitational wave detectors, resulting in displacements with a characteristic frequency set by the gauge boson mass. We outline a novel search strategy for such dark matter, a...

[Phys. Rev. Lett. 121, 061102] Published Wed Aug 08, 2018

]]>The Sub-Electron-Noise Skipper CCD Experimental Instrument (SENSEI) uses the recently developed Skipper-CCD technology to search for electron recoils from the interaction of sub-GeV dark matter particles with electrons in silicon. We report first results from a prototype SENSEI detector, which colle...

[Phys. Rev. Lett. 121, 061803] Published Wed Aug 08, 2018

]]>We propose a new method to produce an electric and magnetic dipolar gas of ultracold dysprosium atoms. The pair of nearly degenerate energy levels of opposite parity, at $17513.33\text{\hspace{0.17em}}\text{\hspace{0.17em}}{\mathrm{cm}}^{-1}$ with electronic angular momentum $J=10$, and at $17514.50\text{\hspace{0.17em}}\text{\hspace{0.17em}}{\mathrm{cm}}^{-1}$ with $J=9$, can be mixed with an external electric field...

[Phys. Rev. Lett. 121, 063201] Published Wed Aug 08, 2018

]]>Clusters and nanoparticles have been widely investigated to determine how plasmonic near fields influence the strong-field induced energetic electron emission from finite systems. We focus on the contrary, i.e., the slow electrons, and discuss a hitherto unidentified low-energy structure (LES) in th...

[Phys. Rev. Lett. 121, 063202] Published Wed Aug 08, 2018

]]>We explore the dynamical response of dissipative Kerr solitons to changes in pump power and detuning and show how thermal and nonlinear processes couple these parameters to the frequency-comb degrees of freedom. Our experiments are enabled by a Pound-Drever-Hall (PDH) stabilization approach that pro...

[Phys. Rev. Lett. 121, 063902] Published Wed Aug 08, 2018

]]>The radiation pressure force on a nearly single-order diffraction grating was measured for a transmission grating near the Littrow angles at wavelengths of 808 and 447 nm. The component of force parallel to the grating agreed well with our prediction, being proportional to the product of the grating...

[Phys. Rev. Lett. 121, 063903] Published Wed Aug 08, 2018

]]>A mechanical analogue to the Purcell effect is proposed, for which elastic radiation from a localized emitter is modified by generic resonant microantennas.

[Phys. Rev. Lett. 121, 064301] Published Wed Aug 08, 2018

]]>Researchers have identified a regime under which a magnetic stir bar can be made to levitate while it spins in a fluid.

[Phys. Rev. Lett. 121, 064502] Published Wed Aug 08, 2018

]]>We demonstrated selective slice-dependent lasing by controlling the matching to the undulator of different slices within an electron bunch. The slice-dependent mismatch was realized through quadrupole wakefield generated in a corrugated structure. A deterministic procedure based on empirical beam tr...

[Phys. Rev. Lett. 121, 064802] Published Wed Aug 08, 2018

]]>The hose instability of the drive beam constitutes a major challenge for the stable operation of plasma-wakefield accelerators. In this Letter, we show that drive beams with a transverse size comparable to the plasma blowout radius generate a wake with a varying focusing along the beam, which leads ...

[Phys. Rev. Lett. 121, 064803] Published Wed Aug 08, 2018

]]>The phase diagram of isotropically expanded graphene cannot be correctly predicted by ignoring either electron correlations, or mobile carbons, or the effect of applied stress, as was done so far. We calculate the ground state enthalpy (not just energy) of strained graphene by an accurate off-lattic...

[Phys. Rev. Lett. 121, 066402] Published Wed Aug 08, 2018

]]>Recent advances in ultrafast measurement in cold atoms, as well as pump-probe spectroscopy of ${\mathrm{K}}_{3}{\mathrm{C}}_{60}$ films, have opened the possibility of rapidly quenching systems of interacting fermions to, and across, a finite temperature superfluid transition. However, determining that a transient state has appr...

[Phys. Rev. Lett. 121, 067001] Published Wed Aug 08, 2018

]]>Understanding magnetic interactions in the parent compounds of high-temperature superconductors forms the basis for determining their role for the mechanism of superconductivity. For parent compounds of iron pnictide superconductors such as $A{\mathrm{Fe}}_{2}{\mathrm{As}}_{2}$ ($A=\mathrm{Ba}$, Ca, Sr), although spin excitations have been...

[Phys. Rev. Lett. 121, 067002] Published Wed Aug 08, 2018

]]>This Letter uses density functional, dynamical mean field, and Landau-theory methods to elucidate the interplay of electronic and structural energetics in the Mott metal-insulator transition. A Landau-theory free energy is presented that incorporates the electronic energetics, the coupling of the el...

[Phys. Rev. Lett. 121, 067601] Published Wed Aug 08, 2018

]]>In this Letter, we report a resonant x-ray scattering measurement of stripelike charge order in the 1/8th doped component of electronically phase-separated, orthorhombic ${\mathrm{La}}_{2}{\mathrm{CuO}}_{4+y}$. This observation is coupled to the absence of any resonant (001) peak, which at different resonant energies has been id...

[Phys. Rev. Lett. 121, 067602] Published Wed Aug 08, 2018

]]>The ground state of two-dimensional (2D) electron systems with equal low densities of electrons and holes in nearby layers is an exciton fluid. We show that a reservoir for excitons can be established by contacting the two layers separately and maintaining the chemical potential difference at a valu...

[Phys. Rev. Lett. 121, 067702] Published Wed Aug 08, 2018

]]>The interfacial mechanics of soft elastic networks plays a central role in biological and technological contexts. Yet, effects of solid capillarity have remained controversial, primarily due to the strain-dependent surface energy. Here we derive the equations that govern the selection of contact ang...

[Phys. Rev. Lett. 121, 068003] Published Wed Aug 08, 2018

]]>Active qubit reset is a key operation in many quantum algorithms, and particularly in quantum error correction. Here, we experimentally demonstrate a reset scheme for a three-level transmon artificial atom coupled to a large bandwidth resonator. The reset protocol uses a microwave-induced interactio...

[Phys. Rev. Lett. 121, 060502] Published Tue Aug 07, 2018

]]>The concept of parity describes the inversion symmetry of a system and is of fundamental relevance in the standard model, quantum information processing, and field theory. In quantum electrodynamics, parity is conserved and large field gradients are required to engineer the parity of the light-matte...

[Phys. Rev. Lett. 121, 060503] Published Tue Aug 07, 2018

]]>We show a relation between entanglement and correlations of any form. The internal entanglement of a bipartite system, and its correlations with another system, limit each other. A measure of correlations, of any nature, cannot increase under local operations. Examples are the entanglement monotones...

[Phys. Rev. Lett. 121, 060504] Published Tue Aug 07, 2018

]]>We study spectral statistics in spatially extended chaotic quantum many-body systems, using simple lattice Floquet models without time-reversal symmetry. Computing the spectral form factor $K(t)$ analytically and numerically, we show that it follows random matrix theory (RMT) at times longer than a ma...

[Phys. Rev. Lett. 121, 060601] Published Tue Aug 07, 2018

]]>A proposal to study quasi-bound states of rotating black holes makes use of the background vorticity in a draining bathtub.

[Phys. Rev. Lett. 121, 061101] Published Tue Aug 07, 2018

]]>While winding a particlelike excitation around a looplike excitation yields the celebrated Aharonov-Bohm phase, we find a distinctive braiding phase in the absence of such mutual winding. In this Letter, we propose an exotic particle-loop-loop braiding process, dubbed the *Borromean rings braiding*. I...

[Phys. Rev. Lett. 121, 061601] Published Tue Aug 07, 2018

]]>The pseudorapidity distributions of dijets as functions of their average transverse momentum (${p}_{\mathrm{T}}^{\text{ave}}$) are measured in proton-lead ($p\mathrm{Pb}$) and proton-proton ($pp$) collisions. The data samples were collected by the CMS experiment at the CERN LHC, at a nucleon-nucleon center-of-mass energy of 5.02 TeV. A s...

[Phys. Rev. Lett. 121, 062002] Published Tue Aug 07, 2018

]]>Based on an ${e}^{+}{e}^{-}$ collision data sample corresponding to an integrated luminosity of $567\text{\hspace{0.17em}}\text{\hspace{0.17em}}{\mathrm{pb}}^{-1}$ taken at the center-of-mass energy of $\sqrt{s}=4.6\text{\hspace{0.17em}}\text{\hspace{0.17em}}\mathrm{GeV}$ with the BESIII detector, we measure the absolute branching fraction of the inclusive decay ${\mathrm{\Lambda}}_{c}^{+}\to \mathrm{\Lambda}+X$ to be $\mathcal{B}({\mathrm{\Lambda}}_{c}^{+}\to \mathrm{\Lambda}+X)=(38.{2}_{-2.2}^{+2.8}\pm 0.9)\%$ using the double-tag...

[Phys. Rev. Lett. 121, 062003] Published Tue Aug 07, 2018

]]>We confront observational data from gravitational wave event GW170817 with microscopic modeling of the cold neutron star equation of state. We develop and employ a Bayesian statistical framework that enables us to implement constraints on the equation of state from laboratory measurements of nuclei ...

[Phys. Rev. Lett. 121, 062701] Published Tue Aug 07, 2018

]]>We study synchronization in a two-node network built out of the smallest possible self-sustained oscillator: a spin-1 oscillator. We first demonstrate that phase locking between the quantum oscillators can be achieved, even for limit cycles that cannot be synchronized to an external semiclassical si...

[Phys. Rev. Lett. 121, 063601] Published Tue Aug 07, 2018

]]>Miniaturized mechanical sensors rely on resonant operation schemes, unsuited to detect static forces. We demonstrate a nanomechanical sensor for static forces based on an optically trapped nanoparticle in vacuum. Our technique relies on an off-resonant interaction of the particle with a weak static ...

[Phys. Rev. Lett. 121, 063602] Published Tue Aug 07, 2018

]]>Particle-beam-driven plasma wakefield acceleration (PWFA) enables various novel high-gradient techniques for powering future compact light-source and high-energy physics applications. Here, a driving particle bunch excites a wakefield response in a plasma medium, which may rapidly accelerate a trail...

[Phys. Rev. Lett. 121, 064801] Published Tue Aug 07, 2018

]]>The Landau bands of mirror symmetric 2D Dirac semimetals (e.g., odd layers of $ABA$ graphene) can be identified by their parity with respect to mirror symmetry. This symmetry facilitates a new class of counterpropagating Hall states. We predict the presence of a Laughlin-like correlated liquid state, ...

[Phys. Rev. Lett. 121, 066602] Published Tue Aug 07, 2018

]]>In this work, we demonstrate a new route to realizing an experimentally controllable spin-Hall effect (SHE), on the surface of 3D topological insulators, which depends fundamentally on the spin-orbit-coupled (SOC) nature of the 2D Weyl fermions. Spin transport is solely due to the spin-torque curren...

[Phys. Rev. Lett. 121, 066603] Published Tue Aug 07, 2018

]]>Determining the fate of the Pauling entropy in the classical spin ice material ${\mathrm{Dy}}_{2}{\mathrm{Ti}}_{2}{\mathrm{O}}_{7}$ with respect to the third law of thermodynamics has become an important test case for understanding the existence and stability of ice-rule states in general. The standard model of spin ice—the dipolar spin ice m...

[Phys. Rev. Lett. 121, 067202] Published Tue Aug 07, 2018

]]>Exciton polaritons in high quality semiconductor microcavities can travel long macroscopic distances ($>100\text{\hspace{0.17em}}\text{\hspace{0.17em}}\mu \mathrm{m}$) due to their ultralight effective mass. The polaritons are repelled from optically pumped exciton reservoirs where they are formed; however, their spatial dynamics is not as expected fo...

[Phys. Rev. Lett. 121, 067401] Published Tue Aug 07, 2018

]]>A new spin valve design consists of stacked van der Waals layers of graphene and ferromagnetic insulators.

[Phys. Rev. Lett. 121, 067701] Published Tue Aug 07, 2018

]]>We show that the clogging susceptibility and flow of particles moving through a random obstacle array can be controlled with a transverse or longitudinal ac drive. The flow rate can vary over several orders of magnitude, and we find both an optimal frequency and an optimal amplitude of driving that ...

[Phys. Rev. Lett. 121, 068001] Published Tue Aug 07, 2018

]]>If a thermal gradient is applied along a fluid-solid interface, the fluid experiences a thermo-osmotic force. In the steady state, this force is balanced by the gradient of the shear stress. Surprisingly, there appears to be no unique microscopic expression that can be used for computing the magnitu...

[Phys. Rev. Lett. 121, 068002] Published Tue Aug 07, 2018

]]>In this Letter, we establish and explore a new connection between quantum information theory and classical statistical mechanics by studying the problem of qubit losses in 2D topological color codes. We introduce a protocol to cope with qubit losses, which is based on the identification and removal ...

[Phys. Rev. Lett. 121, 060501] Published Mon Aug 06, 2018

]]>The observation of neutron stars with masses greater than one solar mass places severe demands on any exotic neutron decay mode that could explain the discrepancy between beam and bottle measurements of the neutron lifetime. If the neutron can decay to a stable, feebly interacting dark fermion, the ...

[Phys. Rev. Lett. 121, 061801] Published Mon Aug 06, 2018

]]>Exotic particles carrying baryon number and with a mass of the order of the nucleon mass have been proposed for various reasons including baryogenesis, dark matter, mirror worlds, and the neutron lifetime puzzle. We show that the existence of neutron stars with a mass greater than $0.7\text{\hspace{0.17em}}\text{\hspace{0.17em}}{M}_{\odot}$ places sev...

[Phys. Rev. Lett. 121, 061802] Published Mon Aug 06, 2018

]]>We report the first observation of the hadronic transition $\mathrm{\Upsilon}(4S)\to {\eta}^{\prime}\mathrm{\Upsilon}(1S)$, using $496\text{\hspace{0.17em}}\text{\hspace{0.17em}}{\mathrm{fb}}^{-1}$ data collected at the $\mathrm{\Upsilon}(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy ${e}^{+}{e}^{-}$ collider. We reconstruct the ${\eta}^{\prime}$ meson through its decays to ${\rho}^{0}\gamma $ and to ${\pi}^{+}{\pi}^{-}\eta $, with $\eta \to \gamma \gamma $. We measure $\mathcal{B}(\mathrm{\Upsilon}(4S)\to {\eta}^{\prime}\mathrm{\Upsilon}(1\mathrm{...}$

[Phys. Rev. Lett. 121, 062001] Published Mon Aug 06, 2018

]]>Complicated multipath trajectories of waves in disordered cavities cause object localization to be very challenging with traditional ray-tracing approaches. Yet it is known that information about the object position is encoded in the Green’s function. After a calibration step, traditional time-rever...

[Phys. Rev. Lett. 121, 063901] Published Mon Aug 06, 2018

]]>The dispute on whether the three-dimensional (3D) incompressible Euler equations develop an infinitely large vorticity in a finite time (blowup) keeps increasing due to ambiguous results from state-of-the-art direct numerical simulations (DNS), while the available simplified models fail to explain t...

[Phys. Rev. Lett. 121, 064501] Published Mon Aug 06, 2018

]]>Thin films of poly(methyl methacrylate) and poly(vinyl chloride) of different thickness are used to investigate the effect of spatial confinement on the efficiency of bond breaking induced by 2 MeV ${\mathrm{H}}^{+}$ and 2.1 GeV Bi ions. Effective cross sections for oxygen and chlorine loss are extracted for films ...

[Phys. Rev. Lett. 121, 066101] Published Mon Aug 06, 2018

]]>Dislocation defects are often a nuisance in semiconductors, but theoretical work shows they might offer an improved route to producing spin currents.

[Phys. Rev. Lett. 121, 066401] Published Mon Aug 06, 2018

]]>An exact formula for the temperature dependent Hall number of metals is derived. It is valid for nonrelativistic fermions or bosons, with an arbitrary potential and interaction. This dc transport coefficient is proven to (remarkably) depend solely on equilibrium susceptibilities, which are more amen...

[Phys. Rev. Lett. 121, 066601] Published Mon Aug 06, 2018

]]>Quantum spin ice materials, pyrochlore magnets with competing Ising and transverse exchange interactions, have been widely discussed as candidates for a quantum spin-liquid ground state. Here, motivated by quantum chemical calculations for Pr pyrochlores, we present the results of a study for frustr...

[Phys. Rev. Lett. 121, 067201] Published Mon Aug 06, 2018

]]>We investigate numerically and analytically the heating process in ergodic clusters of interacting spins $1/2$ subjected to periodic pulses of an external magnetic field. Our findings indicate that there is a threshold for the pulse strength below which the heating is suppressed. This threshold decrea...

[Phys. Rev. Lett. 121, 050602] Published Fri Aug 03, 2018

]]>Quantum gravity corrections have been speculated to lead to modifications to space-time geometry near black-hole horizons. Such structures may reflect gravitational waves, causing *echoes* that follow the main gravitational waves from binary black-hole coalescence. By studying two phenomenological mod...

[Phys. Rev. Lett. 121, 051105] Published Fri Aug 03, 2018

]]>We present the first limits on inelastic electron-scattering dark matter and dark photon absorption using a prototype SuperCDMS detector having a charge resolution of 0.1 electron-hole pairs (CDMS HVeV, a 0.93 g CDMS high-voltage device). These electron-recoil limits significantly improve experiment...

[Phys. Rev. Lett. 121, 051301] Published Fri Aug 03, 2018

]]>The Ooguri-Vafa swampland conjectures claim that in any consistent theory of quantum gravity, when venturing to large distances in scalar field space, a tower of particles will become light at a rate that is exponential in the field-space distance. We provide a novel viewpoint on this claim: If we a...

[Phys. Rev. Lett. 121, 051601] Published Fri Aug 03, 2018

]]>We argue that entropy production in hydrodynamics can be understood via a superspace inflow mechanism. Our arguments are based on a recently developed formalism for constructing effective actions for Schwinger-Keldysh observables in quantum field theories. The formalism explicitly incorporates micro...

[Phys. Rev. Lett. 121, 051602] Published Fri Aug 03, 2018

]]>We study the relevance of experimental data on heavy-flavor [${D}^{0}$, $J/\psi $, $B\to J/\psi $ and $\mathrm{\Upsilon}(1S)$ mesons] production in proton-lead collisions at the LHC to improve our knowledge of the gluon-momentum distribution inside heavy nuclei. We observe that the nuclear effects encoded in both most recent global fits o...

[Phys. Rev. Lett. 121, 052004] Published Fri Aug 03, 2018

]]>We report spectroscopic results on the $2s2p{{}^{1}P}_{1}$ state in neutral atomic beryllium-9. The absolute frequency for the center of gravity is determined to be $42\text{\hspace{0.17em}}565.4501(13)\text{\hspace{0.17em}}\text{\hspace{0.17em}}{\mathrm{cm}}^{-1}$, a factor of 130 more precise than the previous experimental measurement. The result is in agreement with and a factor of 8 m...

[Phys. Rev. Lett. 121, 053001] Published Fri Aug 03, 2018

]]>Computer modeling shows that surprisingly large regions can trap particles floating in a fluid that is moving steadily through a pipe junction.

[Phys. Rev. Lett. 121, 054502] Published Fri Aug 03, 2018

]]>The current drive efficiency at high density in a diverted tokamak is maintained with improved control and by limiting the ill effects of the plasma-wall boundary and turbulence.

[Phys. Rev. Lett. 121, 055001] Published Fri Aug 03, 2018

]]>The ultrafast dynamics of the octahedral rotation in $\mathrm{Ca}:\mathrm{SrTi}{\mathrm{O}}_{3}$ is studied by time-resolved x-ray diffraction after photoexcitation over the band gap. By monitoring the diffraction intensity of a superlattice reflection that is directly related to the structural order parameter of the soft-mode drive...

[Phys. Rev. Lett. 121, 055701] Published Fri Aug 03, 2018

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