We introduce a new kind of quantum measurement that is defined to be symmetric in the sense of uniform Fisher information across a set of parameters that uniquely represent pure quantum states in the neighborhood of a fiducial pure state. The measurement is locally informationally complete—i.e., it …

[Phys. Rev. Lett. 116, 180402] Published Thu May 05, 2016

]]>Extracting the unique information on ultradense nuclear matter from the gravitational waves emitted by merging neutron-star binaries requires robust theoretical models of the signal. We develop a novel effective-one-body waveform model that includes, for the first time, *dynamic* (instead of only adia…

[Phys. Rev. Lett. 116, 181101] Published Thu May 05, 2016

]]>T2K reports its first measurements of the parameters governing the disappearance of ${\overline{\nu}}_{\mu}$ in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic ${\overline{\nu}}_{\mu}$ beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 …

[Phys. Rev. Lett. 116, 181801] Published Thu May 05, 2016

]]>Two different experiments observe nuclei with excited nuclear states that differ in shape from their ground states, so called shape coexistence. These nuclei lie close to the neutron-rich doubly-magic ${}^{78}$Ni region of the nuclear chart.

[Phys. Rev. Lett. 116, 182501] Published Thu May 05, 2016

]]>Two different experiments observe nuclei with excited nuclear states that differ in shape from their ground states, so called shape coexistence. These nuclei lie close to the neutron-rich doubly-magic ${}^{78}$Ni region of the nuclear chart.

[Phys. Rev. Lett. 116, 182502] Published Thu May 05, 2016

]]>We use an optical centrifuge to align asymmetric top ${\mathrm{SO}}_{2}$ molecules by adiabatically spinning their most polarizable O-O axis. The effective centrifugal potential in the rotating frame confines the sulfur atoms to the plane of the laser-induced rotation, leading to the planar molecular alignment that…

[Phys. Rev. Lett. 116, 183001] Published Thu May 05, 2016

]]>Spatiotemporal mode coupling in highly multimode physical systems permits new routes for exploring complex instabilities and forming coherent wave structures. We present here the first experimental demonstration of multiple geometric parametric instability sidebands, generated in the frequency domai…

[Phys. Rev. Lett. 116, 183901] Published Thu May 05, 2016

]]>High-intensity trains of electron bunches with tunable picosecond spacing are produced and measured experimentally with the goal of generating terahertz (THz) radiation. By imposing an initial density modulation on a relativistic electron beam and controlling the charge density over the beam propaga…

[Phys. Rev. Lett. 116, 184801] Published Thu May 05, 2016

]]>Tuning a plasma on the nanoscale level can transform a plasma mirror from an extreme ultraviolet emitter to an efficient electron accelerator.

[Phys. Rev. Lett. 116, 185001] Published Thu May 05, 2016

]]>The reversed field pinch (RFP) device RFX-mod features strong internal transport barriers when the plasma accesses states with a single dominant helicity. Such transport barriers enclose a hot helical region with high confinement whose amplitude may vary from a tiny one to an amplitude encompassing …

[Phys. Rev. Lett. 116, 185002] Published Thu May 05, 2016

]]>A search of the 230 crystallographic symmetry groups find seven that can host double Dirac points. These materials have the same properties as single Dirac semimetals, but can be tuned to simultaneously be topological and trivial insulators.

[Phys. Rev. Lett. 116, 186402] Published Thu May 05, 2016

]]>We report a large enhancement of thermally injected spin current in normal metal (NM)/antiferromagnet (AF)/yttrium iron garnet (YIG), where a thin AF insulating layer of NiO or CoO can enhance the spin current from YIG to a NM by up to a factor of 10. The spin current enhancement in $\mathrm{NM}/\mathrm{AF}/\mathrm{YIG}$, with …

[Phys. Rev. Lett. 116, 186601] Published Thu May 05, 2016

]]>Sharp resonance peaks in electrical conductance identify the energies and nature of the emitted phonons in graphene-based transistors.

[Phys. Rev. Lett. 116, 186603] Published Thu May 05, 2016

]]>Kinks near the Fermi level observed in angle-resolved photoemission spectroscopy (ARPES) have been widely accepted to represent electronic coupling to collective excitations, but kinks at higher energies have eluded a unified description. We identify the mechanism leading to such kink features by me…

[Phys. Rev. Lett. 116, 186802] Published Thu May 05, 2016

]]>We study the effect of a nonmagnetic impurity inserted in a two-dimensional frustrated ferromagnet above its saturation magnetic field ${H}_{\mathrm{sat}}$ for arbitrary spin $S$. We demonstrate that the ground state includes a magnetic vortex that is nucleated around the impurity over a finite range of magnetic fiel…

[Phys. Rev. Lett. 116, 187202] Published Thu May 05, 2016

]]>Colloidal shear thickening presents a significant challenge because the macroscopic rheology becomes increasingly controlled by the microscopic details of short ranged particle interactions in the shear thickening regime. Our measurements here of the first normal stress difference over a wide range …

[Phys. Rev. Lett. 116, 188301] Published Thu May 05, 2016

]]>We report on the first microscale observation of the velocity field imposed by a nonuniform heat content along the solid-liquid boundary. We determine both radial and vertical velocity components of this thermo-osmotic flow field by tracking single tracer nanoparticles. The measured flow profiles ar…

[Phys. Rev. Lett. 116, 188303] Published Thu May 05, 2016

]]>[Phys. Rev. Lett. 116, 189801] Published Thu May 05, 2016

]]>[Phys. Rev. Lett. 116, 189802] Published Thu May 05, 2016

]]>An array of optical waveguides bestows light waves with three spin-like states, which are observable in cone- and vortex-shaped diffraction patterns.

[Phys. Rev. Lett. 116, 183902] Published Wed May 04, 2016

]]>Weak value measurements have recently given rise to a great amount of interest in both the possibility of measurement amplification and the chance for further quantum mechanics foundations investigation. In particular, a question emerged about weak values being proof of the incompatibility between q…

[Phys. Rev. Lett. 116, 180401] Published Mon May 02, 2016

]]>We propose to increase the fidelity of two-qubit resonator-induced phase gates in circuit QED by the use of narrow-band single-mode squeezing. We show that there exists an optimal squeezing angle and strength that erases qubit “which-path” information leaking out of the cavity and thereby minimizes …

[Phys. Rev. Lett. 116, 180501] Published Mon May 02, 2016

]]>We derive the exact mass-coupling relation of the simplest multiscale quantum integrable model, i.e., the homogeneous sine-Gordon model with two mass scales. The relation is obtained by comparing the perturbed conformal field theory description of the model valid at short distances to the large dist…

[Phys. Rev. Lett. 116, 181601] Published Mon May 02, 2016

]]>In this Letter we provide a complete holographic reconstruction of the cubic couplings in the minimal bosonic higher spin theory in ($d+1$)-dimensional anti– de Sitter space. For this purpose, we also determine the operator-product expansion coefficients of all single-trace conserved currents in the $d$…

[Phys. Rev. Lett. 116, 181602] Published Mon May 02, 2016

]]>We observe interference in the light scattered from trapped ${{}^{40}\mathrm{Ca}}^{+}$ ion crystals. By varying the intensity of the excitation laser, we study the influence of elastic and inelastic scattering on the visibility of the fringe pattern and discriminate its effect from that of the ion temperature and wave-p…

[Phys. Rev. Lett. 116, 183002] Published Mon May 02, 2016

]]>We show that the resonance shifts in the fluorescence of a cold gas of rubidium atoms substantially differ from those of thermal atomic ensembles that obey the standard continuous medium electrodynamics. The analysis is based on large-scale microscopic numerical simulations and experimental measurem…

[Phys. Rev. Lett. 116, 183601] Published Mon May 02, 2016

]]>A sideband cooling strategy that incorporates (i) the dynamics induced by structured (non-Markovian) environments in the target and auxiliary systems and (ii) the optimally time-modulated interaction between them is developed. For the context of cavity optomechanics, when non-Markovian dynamics are …

[Phys. Rev. Lett. 116, 183602] Published Mon May 02, 2016

]]>A thin vibrating plate can organize microscopic particles within a liquid into different patterns, an effect like that observed in 18th century studies of musical instruments.

[Phys. Rev. Lett. 116, 184501] Published Mon May 02, 2016

]]>The contact angle of a liquid drop moving on a real solid surface depends on the speed and direction of motion of the three-phase contact line. Many experiments have demonstrated that pinning on surface defects, thermal activation and viscous dissipation impact contact line dynamics, but so far, eff…

[Phys. Rev. Lett. 116, 184502] Published Mon May 02, 2016

]]>Comprehensive studies of lattice dynamics in the ferromagnetic semiconductor EuO have been performed by a combination of inelastic x-ray scattering, nuclear inelastic scattering, and *ab initio* calculations. A remarkably large broadening of the transverse acoustic phonons was discovered at temperatur…

[Phys. Rev. Lett. 116, 185501] Published Mon May 02, 2016

]]>We have measured conductivity spectra of several supercooled monocationic and dicationic ionic liquids in the nonlinear regime by applying ac electric fields with large amplitudes up to about $180\text{\hspace{0.17em}}\text{\hspace{0.17em}}\mathrm{kV}/\mathrm{cm}$. Thereby, higher harmonic ac currents up to the 7th order were detected. Our results point to the…

[Phys. Rev. Lett. 116, 185901] Published Mon May 02, 2016

]]>Charge carrier localization in extended atomic systems has been described previously as being driven by disorder, point defects, or distortions of the ionic lattice. Here we show for the first time by means of first-principles computations that charge carriers can spontaneously localize due to a pur…

[Phys. Rev. Lett. 116, 186401] Published Mon May 02, 2016

]]>Reducing the thickness of the interlayer barrier in a quantum Hall bilayer and tweaking an in-plane magnetic field provides unexpected control over domain formation.

[Phys. Rev. Lett. 116, 186801] Published Mon May 02, 2016

]]>The relatively low magnetocrystalline anisotropy (MCA) in strongly correlated manganites $(\mathrm{La},\mathrm{Sr}){\mathrm{MnO}}_{3}$ has been a major hurdle for implementing them in spintronic applications. Here we report an unusual, giant enhancement of in-plane MCA in 6 nm ${\mathrm{La}}_{0.67}{\mathrm{Sr}}_{0.33}{\mathrm{MnO}}_{3}$ (LSMO) films grown on (001) ${\mathrm{SrTiO}}_{3}$ subs…

[Phys. Rev. Lett. 116, 187201] Published Mon May 02, 2016

]]>[Phys. Rev. Lett. 116, 189901] Published Mon May 02, 2016

]]>[Phys. Rev. Lett. 116, 189902] Published Mon May 02, 2016

]]>[Phys. Rev. Lett. 116, 189903] Published Mon May 02, 2016

]]>Randomness is both a useful way to model natural systems and a useful tool for engineered systems, e.g., in computation, communication, and control. Fully random transformations require exponential time for either classical or quantum systems, but in many cases pseudorandom operations can emulate ce…

[Phys. Rev. Lett. 116, 170502] Published Fri Apr 29, 2016

]]>We present a QCD calculation of the $u$, $d$, and $s$ scalar quark contents of nucleons based on 47 lattice ensembles with ${N}_{f}=2+1$ dynamical sea quarks, 5 lattice spacings down to 0.054 fm, lattice sizes up to 6 fm, and pion masses down to 120 MeV. Using the Feynman-Hellmann theorem, we obtain ${f}_{ud}^{N}=0.0405(\mathrm{\dots}$

[Phys. Rev. Lett. 116, 172001] Published Thu Apr 28, 2016

]]>Precision measurements of superallowed Fermi $\beta $-decay transitions, particularly for the lightest superallowed emitters ${}^{10}\mathrm{C}$ and ${}^{14}\mathrm{O}$, set stringent limits on possible scalar current contributions to the weak interaction. In the present work, a discrepancy between recent measurements of the ${}^{10}\mathrm{C}$ half-lif…

[Phys. Rev. Lett. 116, 172501] Published Thu Apr 28, 2016

]]>We present an experiment using a sample of laser-cooled Rb atoms to show that cross-phase modulation schemes continue to benefit from electromagnetically induced transparency (EIT) even as the transparency window is made narrower than the signal bandwidth (i.e., for signal pulses much shorter than t…

[Phys. Rev. Lett. 116, 173002] Published Thu Apr 28, 2016

]]>The index of refraction in a gas of bosons is enhanced relative to its value in a classical gas, a predicted quantum effect that has now been observed in ultracold sodium atoms.

[Phys. Rev. Lett. 116, 173602] Published Thu Apr 28, 2016

]]>Dispersive shock waves and solitons are fundamental nonlinear excitations in dispersive media, but dispersive shock wave studies to date have been severely constrained. Here, we report on a novel dispersive hydrodynamic test bed: the effectively frictionless dynamics of interfacial waves between two…

[Phys. Rev. Lett. 116, 174501] Published Thu Apr 28, 2016

]]>We show that the space-charge dynamics of high-intensity beams in the plane perpendicular to the magnetic field in cyclotrons is described by the two-dimensional Euler equations for an incompressible fluid. This analogy with fluid dynamics gives a unified and intuitive framework to explain the beam …

[Phys. Rev. Lett. 116, 174801] Published Thu Apr 28, 2016

]]>We consider periodically driven arrays of weakly coupled wires with conduction and valence bands of Rashba type and study the resulting Floquet states. This nonequilibrium system can be tuned into nontrivial phases such as topological insulators, Weyl semimetals, and dispersionless zero-energy edge …

[Phys. Rev. Lett. 116, 176401] Published Thu Apr 28, 2016

]]>We report an atomic-scale characterization of ${\mathrm{ZrTe}}_{5}$ by using scanning tunneling microscopy. We observe a bulk band gap of $\sim 80\text{\hspace{0.17em}}\text{\hspace{0.17em}}\mathrm{meV}$ with topological edge states at the step edge and, thus, demonstrate that ${\mathrm{ZrTe}}_{5}$ is a two-dimensional topological insulator. We also find that an applied magnetic field i…

[Phys. Rev. Lett. 116, 176803] Published Thu Apr 28, 2016

]]>We report on a general principle using interlayer exchange coupling to extend the regime of chiral magnetic films in which stable or metastable magnetic Skyrmions can appear at a zero magnetic field. We verify this concept on the basis of a first-principles model for a Mn monolayer on a W(001) subst…

[Phys. Rev. Lett. 116, 177202] Published Thu Apr 28, 2016

]]>We study the low-temperature physics of the SU(2)-symmetric spin-$1/2$ Heisenberg antiferromagnet on a pyrochlore lattice and find “fingerprint” evidence for the thermal spin-ice state in this frustrated quantum magnet. Our conclusions are based on the results of bold diagrammatic Monte Carlo simulati…

[Phys. Rev. Lett. 116, 177203] Published Thu Apr 28, 2016

]]>We report the first observation of two-phonon quantum coherences in a semiconductor. Two-dimensional terahertz (THz) spectra recorded with a sequence of three THz pulses display strong two-phonon signals, clearly distinguished from signals due to interband two-photon absorption and electron tunnelin…

[Phys. Rev. Lett. 116, 177401] Published Thu Apr 28, 2016

]]>Electron spin plays important roles in determining the physical and chemical properties of matter. However, measurements of electron spin are of poor quality, impeding the development of material sciences, because the spin polarimeter has a low efficiency. Here, we show an imaging-type exchange-scat…

[Phys. Rev. Lett. 116, 177601] Published Thu Apr 28, 2016

]]>A theoretical database is presented of the 212 distinct types of symmetry reductions that could occur for a symmetry-breaking structural phase transition, revealing 124 symmetry reductions that are ferroaxial.

[Phys. Rev. Lett. 116, 177602] Published Thu Apr 28, 2016

]]>[Phys. Rev. Lett. 116, 179901] Published Thu Apr 28, 2016

]]>We consider a thought experiment where two distinct species of 2D particles in a perpendicular magnetic field interact via repulsive potentials. If the magnetic field and the interactions are strong enough, one type of particles forms a Laughlin state and the other type couples to Laughlin quasihole…

[Phys. Rev. Lett. 116, 170401] Published Wed Apr 27, 2016

]]>Based on quantum statistical mechanics and microscopic quantum dynamics, we prove Planck’s and Kelvin’s principles for macroscopic systems in a general and realistic setting. We consider a hybrid quantum system that consists of the thermodynamic system, which is initially in thermal equilibrium, and…

[Phys. Rev. Lett. 116, 170402] Published Wed Apr 27, 2016

]]>Recently detected gravitational waves might not be a signature of black holes but of other massive objects that lack an event horizon.

[Phys. Rev. Lett. 116, 171101] Published Wed Apr 27, 2016

]]>Proton-proton collisions at the highest available LHC energy produce strongly correlated particles that are reminiscent of those seen in similar collisions with protons and lead.

[Phys. Rev. Lett. 116, 172301] Published Wed Apr 27, 2016

]]>Results on two-particle angular correlations for charged particles produced in $pp$ collisions at a center-of-mass energy of 13 TeV are presented. The data were taken with the CMS detector at the LHC and correspond to an integrated luminosity of about $270\text{\hspace{0.17em}}\text{\hspace{0.17em}}{\mathrm{nb}}^{-1}$. The correlations are studied over a bro…

[Phys. Rev. Lett. 116, 172302] Published Wed Apr 27, 2016

]]>There is considerable fundamental and applicative interest in obtaining nondiffractive and nondispersive spatiotemporal localized wave packets propagating in optical cubic nonlinear or Kerr media. Here, we analytically predict the existence of a novel family of spatiotemporal dark lump solitary wave…

[Phys. Rev. Lett. 116, 173901] Published Wed Apr 27, 2016

]]>We investigate the reflection of gravity-capillary surface waves by a plane vertical barrier. The size of the meniscus is found to strongly affect reflection: the energy of the reflected wave with a pinned contact line is around twice the one corresponding to a fully developed meniscus. To perform t…

[Phys. Rev. Lett. 116, 174301] Published Wed Apr 27, 2016

]]>Tokamak experiments at near-unity aspect ratio $A\lesssim 1.2$ offer new insights into the self-organized $H$-mode plasma confinement regime. In contrast to conventional $A\sim 3$ plasmas, the $L\text{\u2212}H$ power threshold ${P}_{LH}$ is $\sim 15\times $ higher than scaling predictions, and it is insensitive to magnetic topology, consistent with …

[Phys. Rev. Lett. 116, 175001] Published Wed Apr 27, 2016

]]>We explore the correlation between a boson peak and structural relaxation in a typical metallic glass. Consistent with enthalpy recovery, a boson peak shows a memory effect in an aging-and-scan procedure. Single-step isothermal aging produces a monotonic decrease of enthalpy and boson peak intensity…

[Phys. Rev. Lett. 116, 175901] Published Wed Apr 27, 2016

]]>By numerical simulations and analytical studies, we show that the phenomenon of microwave-induced resistance oscillations can be understood as a classical memory effect caused by recollisions of electrons with scattering centers after a cyclotron period. We develop a Drude-like approach to magnetotr…

[Phys. Rev. Lett. 116, 176801] Published Wed Apr 27, 2016

]]>Measurements of the Hall and dissipative conductivity of a strained Ge quantum well on a $\mathrm{SiGe}/(001)\mathrm{Si}$ substrate in the quantum Hall regime are reported. We analyze the results in terms of thermally activated quantum tunneling of carriers from one internal edge state to another across saddle points i…

[Phys. Rev. Lett. 116, 176802] Published Wed Apr 27, 2016

]]>We theoretically consider the superconductivity of the topological half-Heusler semimetals YPtBi and LuPtBi. We show that pairing occurs between $j=3/2$ fermion states, which leads to qualitative differences from the conventional theory of pairing between $j=1/2$ states. In particular, this permits Coop…

[Phys. Rev. Lett. 116, 177001] Published Wed Apr 27, 2016

]]>The underlying Dirac point is central to the profound physics manifested in a wide class of materials. However, it is often difficult to drive a system with Dirac points across the massless fermionic critical point. Here by exploiting screening of local moments under spin-orbit interactions in a Kon…

[Phys. Rev. Lett. 116, 177002] Published Wed Apr 27, 2016

]]>We propose a universal nonlinear sigma model field theory for one-dimensional frustrated ferromagnets, which applies in the vicinity of a “quantum Lifshitz point,” at which the ferromagnetic state develops a spin wave instability. We investigate the phase diagram resulting from perturbations of the …

[Phys. Rev. Lett. 116, 177201] Published Wed Apr 27, 2016

]]>We introduce and illustrate a new approach to the unknotting problem via the dynamics of vortex strings in a nonlinear partial differential equation of reaction-diffusion type. To untangle a given knot, a Biot-Savart construction is used to initialize the knot as a vortex string in the FitzHugh-Nagu…

[Phys. Rev. Lett. 116, 178101] Published Wed Apr 27, 2016

]]>Within a unified formulation—encompassing self-electrophoresis, self-diffusiophoresis, and self-thermophoresis—we provide a simple integral kernel transforming the relevant surface flux to particle velocity for any spheroid with axisymmetric surface activity and uniform phoretic mobility. Appropriat…

[Phys. Rev. Lett. 116, 178302] Published Wed Apr 27, 2016

]]>We show that there exists an infinite tower of fermionic symmetries in pure $d=4$, $\mathcal{N}=1$ supergravity on an asymptotically flat background. The Ward identities associated with these symmetries are equivalent to the soft limit of the gravitino and to the statement of supersymmetry at every angle. Additio…

[Phys. Rev. Lett. 116, 171601] Published Tue Apr 26, 2016

]]>We revisit the concept of near-forward rescattering strong-field photoelectron holography introduced by Y. Huismans *et al.* [Science **331**, 61 (2011)]. The recently developed adiabatic theory is used to show how the phase of the scattering amplitude for near-forward rescattering of an ionized electron …

[Phys. Rev. Lett. 116, 173001] Published Tue Apr 26, 2016

]]>[Phys. Rev. Lett. 116, 179801] Published Tue Apr 26, 2016

]]>[Phys. Rev. Lett. 116, 179802] Published Tue Apr 26, 2016

]]>Pure quantum states play a central role in applications of quantum information, both as initial states for quantum algorithms and as resources for quantum error correction. Preparation of highly pure states that satisfy the threshold for quantum error correction remains a challenge, not only for ens…

[Phys. Rev. Lett. 116, 170501] Published Mon Apr 25, 2016

]]>Stochastic restart may drastically reduce the expected run time of a computer algorithm, expedite the completion of a complex search process, or increase the turnover rate of an enzymatic reaction. These diverse first-passage-time (FPT) processes seem to have very little in common but it is actually…

[Phys. Rev. Lett. 116, 170601] Published Mon Apr 25, 2016

]]>Sound waves from the primordial fluctuations of the Universe imprinted in the large-scale structure, called baryon acoustic oscillations (BAOs), can be used as standard rulers to measure the scale of the Universe. These oscillations have already been detected in the distribution of galaxies. Here we…

[Phys. Rev. Lett. 116, 171301] Published Mon Apr 25, 2016

]]>We employ light-induced double Bragg diffraction of delta-kick collimated Bose-Einstein condensates to create three symmetric Mach-Zehnder interferometers. They rely on (i) first-order, (ii) two successive first-order, and (iii) second-order processes which demonstrate the scalability of the corresp…

[Phys. Rev. Lett. 116, 173601] Published Mon Apr 25, 2016

]]>The engineered simplicity of a cold-atom system described by the 2D Fermi-Hubbard model allows for a precision test of the model’s equation of state.

[Phys. Rev. Lett. 116, 175301] Published Mon Apr 25, 2016

]]>Active self-propelled particles moving along chiral paths self-organize into vortex structures.

[Phys. Rev. Lett. 116, 178301] Published Mon Apr 25, 2016

]]>Incompatible observables can be approximated by compatible observables in joint measurement or measured sequentially, with constrained accuracy as implied by Heisenberg’s original formulation of the uncertainty principle. Recently, Busch, Lahti, and Werner proposed inaccuracy trade-off relations bas…

[Phys. Rev. Lett. 116, 160405] Published Fri Apr 22, 2016

]]>We find two relations between coherence and path information in a multipath interferometer. The first builds on earlier results for the two-path interferometer, which used minimum-error state discrimination between detector states to provide the path information. For visibility, which was used in th…

[Phys. Rev. Lett. 116, 160406] Published Fri Apr 22, 2016

]]>Recent results in quantum information theory characterize quantum coherence in the context of resource theories. Here, we study the relation between quantum coherence and quantum discord, a kind of quantum correlation which appears even in nonentangled states. We prove that the creation of quantum d…

[Phys. Rev. Lett. 116, 160407] Published Fri Apr 22, 2016

]]>We consider the generation of a magnetic field by the flow of a fluid for which the electrical conductivity is nonuniform. A new amplification mechanism is found which leads to dynamo action for flows much simpler than those considered so far. In particular, the fluctuations of the electrical conduc…

[Phys. Rev. Lett. 116, 161102] Published Fri Apr 22, 2016

]]>In the firewall proposal, it is assumed that the firewall lies near the event horizon and should not be observable except by infalling observers, who are presumably terminated at the firewall. However, if the firewall is located near where the horizon would have been, based on the spacetime evolutio…

[Phys. Rev. Lett. 116, 161304] Published Fri Apr 22, 2016

]]>We perform coherent nonlinear spectroscopy of individual excitons strongly confined in single InAs quantum dots (QDs). The retrieval of their intrinsically weak four-wave mixing (FWM) response is enabled by a one-dimensional dielectric waveguide antenna. Compared to a similar QD embedded in bulk med…

[Phys. Rev. Lett. 116, 163903] Published Fri Apr 22, 2016

]]>Single-sided Marchenko equations for Green’s function construction and imaging relate the measured reflection response of a lossless heterogeneous medium to an acoustic wave field inside this medium. I derive two sets of single-sided Marchenko equations for the same purpose, each in a heterogeneous …

[Phys. Rev. Lett. 116, 164301] Published Fri Apr 22, 2016

]]>We introduce and theoretically demonstrate a quantum metamaterial made of dense ultracold neutral atoms loaded into an inherently defect-free artificial crystal of light, immune to well-known critical challenges inevitable in conventional solid-state platforms. We demonstrate an all-optical control,…

[Phys. Rev. Lett. 116, 165502] Published Fri Apr 22, 2016

]]>We measure the quantum capacitance and probe thus directly the electronic density of states of the high mobility, Dirac type two-dimensional electron system, which forms on the surface of strained HgTe. Here we show that observed magnetocapacitance oscillations probe—in contrast to magnetotransport—…

[Phys. Rev. Lett. 116, 166802] Published Fri Apr 22, 2016

]]>Material-based two-level systems (TLSs), appearing as defects in low-temperature devices including superconducting qubits and photon detectors, are difficult to characterize. In this study we apply a uniform dc electric field across a film to tune the energies of TLSs within. The film is embedded in…

[Phys. Rev. Lett. 116, 167002] Published Fri Apr 22, 2016

]]>We study a minimal model for the dynamics of spinons in quantum spin ice. The model captures the essential strong coupling between the spinon and the disordered background spins. We demonstrate that the spinon motion can be mapped to a random walk with an entropy-induced memory in imaginary time. Ou…

[Phys. Rev. Lett. 116, 167202] Published Fri Apr 22, 2016

]]>Water molecules confined in nanochannels exhibit tunneling behavior that smears out the positions of the hydrogen atoms into a pair of corrugated rings.

[Phys. Rev. Lett. 116, 167802] Published Fri Apr 22, 2016

]]>[Phys. Rev. Lett. 116, 169903] Published Fri Apr 22, 2016

]]>Experiments provide evidence for one-way quantum steering—an effect by which distant entangled systems can influence one another in a directional way.

[Phys. Rev. Lett. 116, 160403] Published Thu Apr 21, 2016

]]>Experiments provide evidence for one-way quantum steering—an effect by which distant entangled systems can influence one another in a directional way.

[Phys. Rev. Lett. 116, 160404] Published Thu Apr 21, 2016

]]>Thermodynamics places a limit on the efficiency of heat engines, but not on their output power or on how the power and efficiency change with the engine’s cycle time. In this Letter, we develop a geometrical description of the power and efficiency as a function of the cycle time, applicable to an im…

[Phys. Rev. Lett. 116, 160601] Published Thu Apr 21, 2016

]]>Several quantum gravity scenarios lead to physics below the Planck scale characterized by nonlocal, Lorentz invariant equations of motion. We show that such nonlocal effective field theories lead to a modified Schrödinger evolution in the nonrelativistic limit. In particular, the nonlocal evolution …

[Phys. Rev. Lett. 116, 161303] Published Thu Apr 21, 2016

]]>The first observation of the ${B}_{s}^{0}\to {\overline{D}}^{0}{K}_{S}^{0}$ decay mode and evidence for the ${B}_{s}^{0}\to {\overline{D}}^{*0}{K}_{S}^{0}$ decay mode are reported. The data sample corresponds to an integrated luminosity of $3.0\text{\hspace{0.17em}}\text{\hspace{0.17em}}{\mathrm{fb}}^{-1}$ collected in $pp$ collisions by LHCb at center-of-mass energies of 7 and 8 TeV. The branching fractions are measured to be $$\mathcal{B}\dots $$

[Phys. Rev. Lett. 116, 161802] Published Thu Apr 21, 2016

]]>The first complete calculation of the next-to-leading-order electroweak corrections to four-lepton production at the LHC is presented, where all off-shell effects of intermediate $Z$ bosons and photons are taken into account. Focusing on the mixed final state ${\mu}^{+}{\mu}^{-}{e}^{+}{e}^{-}$, we study differential cross sect…

[Phys. Rev. Lett. 116, 161803] Published Thu Apr 21, 2016

]]>We show that the magnetic component of the photon field produced by dark matter axions via the two-photon coupling mechanism in a Sikivie haloscope is an important parameter passed over in previous analysis and experiments. The interaction of the produced photons will be resonantly enhanced as long …

[Phys. Rev. Lett. 116, 161804] Published Thu Apr 21, 2016

]]>Single top production processes at hadron colliders provide information on the relation between the top quark and the electroweak sector of the standard model. We compute the next-to-leading order QCD corrections to the three main production channels: $t$-channel, $s$-channel, and $tW$ associated producti…

[Phys. Rev. Lett. 116, 162002] Published Thu Apr 21, 2016

]]>We report on the observation of single-photon superradiance from an exciton in a semiconductor quantum dot. The confinement by the quantum dot is strong enough for it to mimic a two-level atom, yet sufficiently weak to ensure superradiance. The electrostatic interaction between the electron and the …

[Phys. Rev. Lett. 116, 163604] Published Thu Apr 21, 2016

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