We demonstrate a cavity-enhanced room-temperature magnetic field sensor based on nitrogen-vacancy centers in diamond. Magnetic resonance is detected using absorption of light resonant with the 1042 nm spin-singlet transition. The diamond is placed in an external optical cavity to enhance the absorpt...

[Phys. Rev. Lett. 112, 160802] Published Wed Apr 23, 2014

]]>We introduce off-axis chromatic scanning confocal electron microscopy, a technique for fast mapping of inelastically scattered electrons in a scanning transmission electron microscope without a spectrometer. The off-axis confocal mode enables the inelastically scattered electrons to be chromatically...

[Phys. Rev. Lett. 112, 166101] Published Tue Apr 22, 2014

]]>The two most prominent and ubiquitous features of glasses at low temperatures, namely the presence of tunneling two-level systems and the so-called boson peak in the reduced vibrational density of states, are shown to persist essentially unchanged in highly stabilized glasses, contrary to what was u...

[Phys. Rev. Lett. 112, 165901] Published Tue Apr 22, 2014

]]>This Letter presents a study of the flavor-changing neutral current radiative B±→K±π∓π±γ decays performed using data collected in proton-proton collisions with the LHCb detector at 7 and 8 TeV center-of-mass energies. In this sample, corresponding to an integrated luminosity of 3 fb−1, nearly 14 00...

[Phys. Rev. Lett. 112, 161801] Published Tue Apr 22, 2014

]]>A measurement-based quantum computer could consist of a local-gapped Hamiltonian system, whose thermal states—at sufficiently low temperature—are universal resources for the computation. Initialization of the computer would correspond to cooling the system. We perform an experimental quantum simulat...

[Phys. Rev. Lett. 112, 160501] Published Tue Apr 22, 2014

]]>Hydrodynamics of the spin-1 Bose-Einstein condensate is investigated without restriction of its allowed manifold to either the ferromagnetic or the antiferromagnetic phase. Mixing of the two manifolds is found to be a generic feature in the temporal evolution of the condensate, regardless of the sig...

[Phys. Rev. Lett. 112, 160402] Published Tue Apr 22, 2014

]]>Although statistical evidence is not overwhelming, possible support for an approximately 35×106 yr periodicity in the crater record on Earth could indicate a nonrandom underlying enhancement of meteorite impacts at regular intervals. A proposed explanation in terms of tidal effects on Oort cloud co...

[Phys. Rev. Lett. 112, 161301] Published Mon Apr 21, 2014

]]>The voter model has been studied extensively as a paradigmatic opinion dynamics model. However, its ability to model real opinion dynamics has not been addressed. We introduce a noisy voter model (accounting for social influence) with recurrent mobility of agents (as a proxy for social context), whe...

[Phys. Rev. Lett. 112, 158701] Published Fri Apr 18, 2014

]]>We show theoretically that periodically driven systems with short range Hubbard interactions offer a feasible platform to experimentally realize fractional Chern insulator states. We exemplify the procedure for both the driven honeycomb and the square lattice, where we derive the effective steady st...

[Phys. Rev. Lett. 112, 156801] Published Fri Apr 18, 2014

]]>Recent experiments demonstrate the production of many thousands of neutral atoms entangled in their spin degrees of freedom. We present a criterion for estimating the amount of entanglement based on a measurement of the global spin. It outperforms previous criteria and applies to a wider class of en...

[Phys. Rev. Lett. 112, 155304] Published Thu Apr 17, 2014

]]>Using path-integral Monte Carlo simulations, we compute the ideal shear strength (ISS) on the basal plane of hcp He4. The failure mode upon reaching the ISS limit is characterized by the homogeneous nucleation of a stacking fault and it is found to be anisotropic, consistent with Schmid’s law of res...

[Phys. Rev. Lett. 112, 155303] Published Thu Apr 17, 2014

]]>We report on precision resonance spectroscopy measurements of quantum states of ultracold neutrons confined above the surface of a horizontal mirror by the gravity potential of Earth. Resonant transitions between several of the lowest quantum states are observed for the first time. These measurement...

[Phys. Rev. Lett. 112, 151105] Published Wed Apr 16, 2014

]]>Identical particles and entanglement are both fundamental components of quantum mechanics. However, when identical particles are condensed in a single spatial mode, the standard notions of entanglement, based on clearly identifiable subsystems, break down. This has led many to conclude that such sys...

[Phys. Rev. Lett. 112, 150501] Published Tue Apr 15, 2014

]]>For the first time in metallic glasses, we extract both the exponents and scaling functions that describe the nature, statistics, and dynamics of slip events during slow deformation, according to a simple mean field model. We model the slips as avalanches of rearrangements of atoms in coupled shear ...

[Phys. Rev. Lett. 112, 155501] Published Mon Apr 14, 2014

]]>Virtual phonons of a quantum liquid scatter off impurities and mediate a long-range interaction, analogous to the Casimir effect. In one dimension the effect is universal and the induced interaction decays as 1/r3, much slower than the van der Waals interaction ∼1/r6, where r is the impurity separat...

[Phys. Rev. Lett. 112, 155301] Published Mon Apr 14, 2014

]]>It is shown that the formation of phase space holes and clumps in kinetically driven, dissipative systems is not restricted to the near threshold regime, as previously reported and widely believed. Specifically, we observe hole-clump generation from the edges of an unmodulated phase space plateau, c...

[Phys. Rev. Lett. 112, 155002] Published Mon Apr 14, 2014

]]>Interaction between a central outflow and a surrounding wind is common in astrophysical sources powered by accretion. Understanding how the interaction might help to collimate the inner central outflow is of interest for assessing astrophysical jet formation paradigms. In this context, we studied th...

[Phys. Rev. Lett. 112, 155001] Published Mon Apr 14, 2014

]]>We present the fabrication and characterization of an artificial crystal structure formed from a thin film of silicon that has a full phononic band gap for microwave X-band phonons and a two-dimensional pseudo-band gap for near-infrared photons. An engineered defect in the crystal structure is used ...

[Phys. Rev. Lett. 112, 153603] Published Mon Apr 14, 2014

]]>We construct turbulent black holes in asymptotically AdS4 spacetime by numerically solving Einstein’s equations. Using the AdS/CFT correspondence we find that both the dual holographic fluid and bulk geometry display signatures of an inverse cascade with the bulk geometry being well approximated by ...

[Phys. Rev. Lett. 112, 151602] Published Mon Apr 14, 2014

]]>We measured the dispersion relation for acoustic longitudinal waves in liquid foams, over a broad frequency range (60–600 kHz). Strong dispersion was found, with two nondispersive behaviors, separated by a negative density regime. A new model, based on the coupled displacements of films, liquid chan...

[Phys. Rev. Lett. 112, 148307] Published Fri Apr 11, 2014

]]>By finding local minima of a thermodynamic-like potential, we generate jammed packings of frictionless spheres under constant shear stress σ and obtain the yield stress σy by sampling the potential energy landscape. For three-dimensional systems with harmonic repulsion, σy satisfies the finite size ...

[Phys. Rev. Lett. 112, 145502] Published Thu Apr 10, 2014

]]>Holonomic phases—geometric and topological—have long been an intriguing aspect of physics. They are ubiquitous, ranging from observations in particle physics to applications in fault tolerant quantum computing. However, their exploration in particles sharing genuine quantum correlations lacks in obs...

[Phys. Rev. Lett. 112, 143603] Published Thu Apr 10, 2014

]]>Entanglement, the essential resource in quantum information processing, should be witnessed in many tasks such as quantum computing and quantum communication. The conventional entanglement witness method, relying on an idealized implementation of measurements, could wrongly conclude a separable stat...

[Phys. Rev. Lett. 112, 140506] Published Thu Apr 10, 2014

]]>Femtosecond laser pulses trigger in dielectric FeBO3 coherent oscillations of the magnetic anisotropy followed by spins. The oscillations are driven by optically excited lattice vibrations strongly coupled to the magnetic system. Unlike the spin resonances, this mode is characterized by a very small...

[Phys. Rev. Lett. 112, 147403] Published Wed Apr 09, 2014

]]>Measurement-based quantum computation (MBQC) is a model of quantum computation, in which computation proceeds via adaptive single qubit measurements on a multiqubit quantum state. It is computationally equivalent to the circuit model. Unlike the circuit model, however, its classical analog is little...

[Phys. Rev. Lett. 112, 140505] Published Wed Apr 09, 2014

]]>We show that hydrodynamic theories of polar active matter generically possess inhomogeneous traveling solutions. We introduce a unifying dynamical-system framework to establish the shape of these intrinsically nonlinear patterns, and show that they correspond to those hitherto observed in experiment...

[Phys. Rev. Lett. 112, 148102] Published Tue Apr 08, 2014

]]>A radiation-reaction trapping (RRT) of electrons is revealed in the near-QED regime of laser-plasma interaction. Electrons quivering in laser pulse experience radiation reaction (RR) recoil force by radiating photons. When the laser field reaches the threshold, the RR force becomes significant enoug...

[Phys. Rev. Lett. 112, 145003] Published Tue Apr 08, 2014

]]>We study the conformal bootstrap in fractional space-time dimensions, obtaining rigorous bounds on operator dimensions. Our results show strong evidence that there is a family of unitary conformal field theories connecting the 2D Ising model, the 3D Ising model, and the free scalar theory in 4D. We ...

[Phys. Rev. Lett. 112, 141601] Published Mon Apr 07, 2014

]]>We introduce a simple model for an engine based on the Nernst effect. In the presence of a magnetic field, a vertical heat current can drive a horizontal particle current against a chemical potential. For a microscopic model invoking classical particle trajectories subject to the Lorentz force, we p...

[Phys. Rev. Lett. 112, 140601] Published Mon Apr 07, 2014

]]>Machines are only Carnot efficient if they are reversible, but then their power output is vanishingly small. Here we ask, what is the maximum efficiency of an irreversible device with finite power output? We use a nonlinear scattering theory to answer this question for thermoelectric quantum systems...

[Phys. Rev. Lett. 112, 130601] Published Fri Apr 04, 2014

]]>Bender et al. [Phys. Rev. Lett. 80, 5243 (1998)

[Phys. Rev. Lett. 112, 130404] Published Thu Apr 03, 2014

]]>Recent experiments on Sandia’s Z facility have confirmed simulation predictions of dramatically reduced instability growth in solid metallic rods when thick dielectric coatings are used to mitigate density perturbations arising from an electrothermal instability. These results provide further eviden...

[Phys. Rev. Lett. 112, 135002] Published Wed Apr 02, 2014

]]>We study the interaction of relativistic electron-vortex beams (EVBs) with laser light. Exact analytical solutions for this problem are obtained by employing the Dirac-Volkov wave functions to describe the (monoenergetic) distribution of the electrons in vortex beams with well-defined orbital angula...

[Phys. Rev. Lett. 112, 134801] Published Wed Apr 02, 2014

]]>We study the process e+e−→(D*D¯*)±π∓ at a center-of-mass energy of 4.26 GeV using a 827 pb−1 data sample obtained with the BESIII detector at the Beijing Electron Positron Collider. Based on a partial reconstruction technique, the Born cross section is measured to be (137±9±15) pb. We observe a st...

[Phys. Rev. Lett. 112, 132001] Published Wed Apr 02, 2014

]]>We present a new paradigm for supersymmetric theories with R-parity violation (RPV). At high scale, R parity is conserved in the visible sector but spontaneously broken in the supersymmetry-breaking sector. The breaking is then dynamically mediated to the visible sector and is manifested via nonreno...

[Phys. Rev. Lett. 112, 131801] Published Wed Apr 02, 2014

]]>We reconstruct the gravitational lensing convergence signal from cosmic microwave background (CMB) polarization data taken by the Polarbear experiment and cross-correlate it with cosmic infrared background maps from the Herschel satellite. From the cross spectra, we obtain evidence for gravitational...

[Phys. Rev. Lett. 112, 131302] Published Wed Apr 02, 2014

]]>The collective dynamics of a network of excitable nodes changes dramatically when inhibitory nodes are introduced. We consider inhibitory nodes which may be activated just like excitatory nodes but, upon activating, decrease the probability of activation of network neighbors. We show that, although ...

[Phys. Rev. Lett. 112, 138103] Published Tue Apr 01, 2014

]]>A low-lying state in In82131, the one-proton hole nucleus with respect to double magic Sn132, was observed by its γ decay to the Iπ=1/2− β-emitting isomer. We identify the new state at an excitation energy of Ex=1353 keV, which was populated both in the β decay of Cd13183 and after β-delayed neutro...

[Phys. Rev. Lett. 112, 132501] Published Tue Apr 01, 2014

]]>Weyl fermions, first proposed for describing massless chiral Dirac fermions in particle physics, have not been observed yet in experiments. Recently, much effort has been devoted to explore Weyl fermions around band touching points of single-particle energy dispersions in certain solid state materia...

[Phys. Rev. Lett. 112, 136402] Published Mon Mar 31, 2014

]]>Materials engineered at the micro- and nanometer scales have had a tremendous and lasting impact in photonics and phononics. At much larger scales, natural soils civil engineered at decimeter to meter scales may interact with seismic waves when the global properties of the medium are modified, or al...

[Phys. Rev. Lett. 112, 133901] Published Mon Mar 31, 2014

]]>We study theoretically the collective dynamics of immotile particles bound to a 2D surface atop a 3D fluid layer. These particles are chemically active and produce a chemical concentration field that creates surface-tension gradients along the surface. The resultant Marangoni stresses create flows t...

[Phys. Rev. Lett. 112, 128304] Published Wed Mar 26, 2014

]]>All known proper ferroelectrics are unable to polarize normal to a surface or interface if the resulting depolarization field is unscreened, but there is no fundamental principle that enforces this behavior. In this work, we introduce hyperferroelectrics, a new class of proper ferroelectrics which p...

[Phys. Rev. Lett. 112, 127601] Published Wed Mar 26, 2014

]]>We present here well-defined Coulomb staircases using an original field-emission experiment on several individual in situ—grown single-wall carbon nanotubes. A unique in situ process was applied nine times to progressively shorten one single-wall carbon nanotube down to ≃10 nm, which increased the ...

[Phys. Rev. Lett. 112, 126805] Published Wed Mar 26, 2014

]]>Here, we study the phase transition kinetics in a supercooled liquid state of triphenyl phosphite by means of time-resolved polarized and depolarized light scattering to address a long-standing controversy on its mechanism, i.e., whether the phenomenon is primarily induced by liquid-liquid transitio...

[Phys. Rev. Lett. 112, 125702] Published Wed Mar 26, 2014

]]>Recently, it was shown that slowly rotating neutron stars exhibit an interesting correlation between their moment of inertia I, their quadrupole moment Q, and their tidal deformation Love number λ (the I-Love-Q relations), independently of the equation of state of the compact object. In the present ...

[Phys. Rev. Lett. 112, 121101] Published Wed Mar 26, 2014

]]>Contextuality is central to both the foundations of quantum theory and to the novel information processing tasks. Despite some recent proposals, it still faces a fundamental problem: how to quantify its presence? In this work, we provide a universal framework for quantifying contextuality. We conduc...

[Phys. Rev. Lett. 112, 120401] Published Wed Mar 26, 2014

]]>We present direct numerical simulations of the coupled Poisson-Nernst-Planck and Navier-Stokes equations for an electrolyte around a polarizable cylinder subject to an external electric field. For high fields, a novel chaotic flow phenomenon is discovered. Our calculations indicate significant impro...

[Phys. Rev. Lett. 112, 128302] Published Mon Mar 24, 2014

]]>We present the theory of corresponding distances for interactions mediated by soft nanostructures in fibrous materials. Based on the fundamental understanding of the mechanism that determines the internal structure of the soft component, our theory allows us to predict the entire force field mediate...

[Phys. Rev. Lett. 112, 128301] Published Mon Mar 24, 2014

]]>We optically generated an electronic state in a single InAs/GaAs self-assembled quantum dot that is a precursor to the deterministic entanglement of the spin of the electron with an emitted photon in the proposal of W. Yao, R.-B. Liu, and L. J. Sham [Phys. Rev. Lett. 95, 030504 (2005).]. A superposi...

[Phys. Rev. Lett. 112, 126801] Published Mon Mar 24, 2014

]]>The formation of extreme localizations in nonlinear dispersive media can be explained and described within the framework of nonlinear evolution equations, such as the nonlinear Schrödinger equation (NLS). Within the class of exact NLS breather solutions on a finite background, which describe the mo...

[Phys. Rev. Lett. 112, 124101] Published Mon Mar 24, 2014

]]>An experiment was performed at the scientific neutron source FRM II in Garching to determine the cumulative antineutrino spectrum of the fission products of U238. Target foils of natural uranium were irradiated with a thermal and a fast neutron beam and the emitted β spectra were recorded with a γ-s...

[Phys. Rev. Lett. 112, 122501] Published Mon Mar 24, 2014

]]>In the standard picture of the crust of a neutron star, matter there is simple: a body-centered-cubic lattice of nuclei immersed in an essentially uniform electron gas. We show that, at densities above that for neutron drip (∼4×1011 g cm−3 or roughly one-thousandth of nuclear matter density), the i...

[Phys. Rev. Lett. 112, 112504] Published Fri Mar 21, 2014

]]>We report the observation of a Hall effect driven by orbital resonance in the quasi-1-dimensional (q1D) organic conductor (TMTSF)2ClO4. Although a conventional Hall effect is not expected in this class of materials due to their reduced dimensionality, we observed a prominent Hall response at certain...

[Phys. Rev. Lett. 112, 116805] Published Thu Mar 20, 2014

]]>Jamming has traditionally been studied as a mechanical phenomenon and characterized with mechanical order parameters. However, this approach is not meaningful in the “mechanical vacuum” of systems below jamming in which all mechanical properties are precisely zero. We find that the network of neares...

[Phys. Rev. Lett. 112, 115701] Published Thu Mar 20, 2014

]]>Single-shot readout of individual qubits is typically the slowest process among the elementary single- and two-qubit operations required for quantum information processing. Here, we use resonance fluorescence from a single-electron charged quantum dot to read out the spin-qubit state in 800 nanoseco...

[Phys. Rev. Lett. 112, 116802] Published Wed Mar 19, 2014

]]>An important theoretical ductility criterion for group V and VI metal-based refractory alloys in body-centered cubic (bcc) lattices is the mechanical failure mode of their perfect crystals under tension along the weakest direction [100]. Pure Mo and W fail by cleavage and are deemed intrinsically br...

[Phys. Rev. Lett. 112, 115503] Published Wed Mar 19, 2014

]]>We study the onset and characteristics of vortices in complex (dusty) plasmas using two-dimensional simulations in a setup modeled after the PK-3 Plus laboratory. A small number of microparticles initially self-arranges in a monolayer around the void. As additional particles are introduced, an exten...

[Phys. Rev. Lett. 112, 115002] Published Wed Mar 19, 2014

]]>Extremely fast rotating molecules whose rotational energy is comparable with the molecular bond strength are known as “superrotors.” It has been speculated that superrotors may exhibit a number of unique properties, yet only indirect evidence of these molecular objects has been reported to date. Her...

[Phys. Rev. Lett. 112, 113004] Published Wed Mar 19, 2014

]]>We study the collective motion of confined spherical microswimmers such as active colloids which we model by so-called squirmers. To simulate hydrodynamic flow fields including thermal noise, we use the method of multiparticle collision dynamics. We demonstrate that hydrodynamic near fields acting b...

[Phys. Rev. Lett. 112, 118101] Published Tue Mar 18, 2014

]]>We propose realizing the quantum anomalous Hall effect by proximity coupling graphene to an antiferromagnetic insulator that provides both broken time-reversal symmetry and spin-orbit coupling. We illustrate our idea by performing ab initio calculations for graphene adsorbed on the (111) surface of ...

[Phys. Rev. Lett. 112, 116404] Published Tue Mar 18, 2014

]]>Using an apparatus that images the momentum distribution of individual, isolated 100-nm-scale plasmas, we make the first experimental observation of shock waves in nanoplasmas. We demonstrate that the introduction of a heating pulse prior to the main laser pulse increases the intensity of the shock ...

[Phys. Rev. Lett. 112, 115004] Published Tue Mar 18, 2014

]]>We report cross sections for pickup of guest molecules on neutral argon and water clusters with the mean sizes in the range from N¯=50 to 600. The experiments are supported by molecular dynamics simulations and analytical models based on the interaction potentials. The cross sections for argon clust...

[Phys. Rev. Lett. 112, 113401] Published Tue Mar 18, 2014

]]>We argue that relativistic nuclear collisions may provide experimental evidence of α clustering in light nuclei. A light α-clustered nucleus has a large intrinsic deformation. When collided against a heavy nucleus at very high energies, this deformation transforms into the deformation of the firebal...

[Phys. Rev. Lett. 112, 112501] Published Tue Mar 18, 2014

]]>We report a new type of nanomechanical resonator system based on one-dimensional chains of only 4 to 7 weakly coupled small molecules. Experimental characterization of the truly nanoscopic resonators is achieved by means of a novel radio-frequency scanning tunneling microscopy detection technique at...

[Phys. Rev. Lett. 112, 117201] Published Mon Mar 17, 2014

]]>We calculate the kaon semileptonic form factor f+(0) from lattice QCD, working, for the first time, at the physical light-quark masses. We use gauge configurations generated by the MILC Collaboration with Nf=2+1+1 flavors of sea quarks, which incorporate the effects of dynamical charm quarks as well...

[Phys. Rev. Lett. 112, 112001] Published Mon Mar 17, 2014

]]>In this Letter, we present an upper limit of ΩGW<1.2×108 on an isotropic stochastic gravitational-wave (GW) background integrated over a year in the frequency range 0.05–1 Hz, which improves current upper limits from high-precision laboratory experiments by about 9 orders of magnitude. The limit ...

[Phys. Rev. Lett. 112, 101102] Published Thu Mar 13, 2014

]]>We present measurements of the local (homogeneous) density-density response function of a Fermi gas at unitarity using spatially resolved Bragg spectroscopy. By analyzing the Bragg response across one axis of the cloud, we extract the response function for a uniform gas which shows a clear signature...

[Phys. Rev. Lett. 112, 100404] Published Thu Mar 13, 2014

]]>We report on the experimental violation of multipartite Bell inequalities by entangled states of trapped ions. First, we consider resource states for measurement-based quantum computation of between 3 and 7 ions and show that all strongly violate a Bell-type inequality for graph states, where the cr...

[Phys. Rev. Lett. 112, 100403] Published Thu Mar 13, 2014

]]>We have used picosecond THz pulses to induce transient field-free orientation of OCS molecules. Coherent optical Raman excitation prepares the molecules in rotational superposition states prior to THz irradiation, substantially enhancing the degree of orientation. The time-dependent alignment and or...

[Phys. Rev. Lett. 112, 103002] Published Wed Mar 12, 2014

]]>We present ab initio lattice calculations of the low-energy even-parity states of O16 using chiral nuclear effective field theory. We find good agreement with the empirical energy spectrum, and with the electromagnetic properties and transition rates. For the ground state, we find that the nucleons ...

[Phys. Rev. Lett. 112, 102501] Published Wed Mar 12, 2014

]]>We study the Anderson-type transition previously found in the spectrum of the QCD quark Dirac operator in the high-temperature, quark-gluon plasma phase. Using finite size scaling for the unfolded level spacing distribution, we show that in the thermodynamic limit there is a genuine mobility edge, w...

[Phys. Rev. Lett. 112, 102002] Published Wed Mar 12, 2014

]]>Our numerical simulations of tidal flow of a stratified fluid over periodic knife-edge ridges and random topography reveal that the time-averaged tidal energy converted into internal gravity wave radiation arises only from the section of a ridge above a virtual seafloor. The average radiated power i...

[Phys. Rev. Lett. 112, 104502] Published Tue Mar 11, 2014

]]>Entangling independent photons is not only of fundamental interest but also of crucial importance for quantum-information science. Two-photon interference is a major method for entangling independent identical photons. If two photons are different in color, perfect two-photon coalescence can no long...

[Phys. Rev. Lett. 112, 103602] Published Mon Mar 10, 2014

]]>We report an indication that the elastic scattering rate of solar B8 neutrinos with electrons in the Super-Kamiokande detector is larger when the neutrinos pass through Earth during nighttime. We determine the day-night asymmetry, defined as the difference of the average day rate and average night r...

[Phys. Rev. Lett. 112, 091805] Published Fri Mar 07, 2014

]]>A consensus is emerging that discontinuous shear thickening (DST) in dense suspensions marks a transition from a flow state where particles remain well separated by lubrication layers, to one dominated by frictional contacts. We show here that reasonable assumptions about contact proliferation predi...

[Phys. Rev. Lett. 112, 098302] Published Thu Mar 06, 2014

]]>We propose a very simple reformulation of general relativity, which completely sequesters from gravity all of the vacuum energy from a matter sector, including all loop corrections and renders all contributions from phase transitions automatically small. The idea is to make the dimensional parameter...

[Phys. Rev. Lett. 112, 091304] Published Thu Mar 06, 2014

]]>Geometrical frustration arises when a local order cannot propagate throughout the space because of geometrical constraints. This phenomenon plays a major role in many systems leading to disordered ground-state configurations. Here, we report a theoretical and experimental study on the behavior of bu...

[Phys. Rev. Lett. 112, 098701] Published Wed Mar 05, 2014

]]>We present numerical simulations that allow us to compute the number of ways in which N particles can pack into a given volume V. Our technique modifies the method of Xu, Frenkel, and Liu [Phys. Rev. Lett. 106, 245502 (2011)

[Phys. Rev. Lett. 112, 098002] Published Wed Mar 05, 2014

]]>A multiparticle spin-trap isomer has been discovered in the proton-unbound nucleus Ta85 73158. The isomer mainly decays by γ-ray emission with a half-life of 6.1(1) μs. Analysis of the γ-ray data shows that the isomer lies 2668 keV above the known 9+ state and has a spin 10ℏ higher and negativ...

[Phys. Rev. Lett. 112, 092501] Published Tue Mar 04, 2014

]]>The Large Underground Xenon (LUX) experiment is a dual-phase xenon time-projection chamber operating at the Sanford Underground Research Facility (Lead, South Dakota). The LUX cryostat was filled for the first time in the underground laboratory in February 2013. We report results of the first WIMP s...

[Phys. Rev. Lett. 112, 091303] Published Tue Mar 04, 2014

]]>Single charge nanoscale detection in ambient conditions is a current frontier in metrology that has diverse interdisciplinary applications. Here, such single charge detection is demonstrated using two nitrogen-vacancy (NV) centers in diamond. One NV center is employed as a sensitive electrometer to ...

[Phys. Rev. Lett. 112, 097603] Published Mon Mar 03, 2014

]]>A determination of the spin and parity of the Λ(1405) is presented using photoproduction data from the CLAS detector at Jefferson Lab. The reaction γ+p→K++Λ(1405) is analyzed in the decay channel Λ(1405)→Σ++π−, where the decay distribution to Σ+π− and the variation of the Σ+ polarization with respec...

[Phys. Rev. Lett. 112, 082004] Published Fri Feb 28, 2014

]]>We report the complex dielectric function of high-quality Na3Ir3O8 single crystals determined by spectroscopic ellipsometry in the spectral range from 15 meV to 2 eV. The far-infrared phonon spectra exhibit highly asymmetric line shapes characteristic of Fano resonances. With decreasing temperature,...

[Phys. Rev. Lett. 112, 087401] Published Wed Feb 26, 2014

]]>The new regime of resonant nuclear photoexcitation rendered possible by x-ray free-electron laser beams interacting with solid state targets is investigated theoretically. Our results unexpectedly show that secondary processes coupling nuclei to the atomic shell in the created cold high-density plas...

[Phys. Rev. Lett. 112, 082501] Published Mon Feb 24, 2014

]]>We demonstrate the active suppression of transmon qubit dephasing induced by dispersive measurement, using parametric amplification and analog feedback. By real-time processing of the homodyne record, the feedback controller reverts the stochastic quantum phase kick imparted by the measurement on th...

[Phys. Rev. Lett. 112, 080501] Published Mon Feb 24, 2014

]]>We investigate a mixture of ultracold fermionic K40 atoms and weakly bound Li6K40 dimers on the repulsive side of a heteronuclear atomic Feshbach resonance. By radio-frequency spectroscopy we demonstrate that the normally repulsive atom-dimer interaction is turned into a strong attraction. The pheno...

[Phys. Rev. Lett. 112, 075302] Published Fri Feb 21, 2014

]]>We use the context of dryland vegetation to study a general problem of complex pattern-forming systems: multiple pattern-forming instabilities that are driven by distinct mechanisms but share the same spectral properties. We find that the co-occurrence of two Turing instabilities when the driving me...

[Phys. Rev. Lett. 112, 078701] Published Thu Feb 20, 2014

]]>We generalize the Power-Zineau-Woolley transformation to obtain a canonical Hamiltonian of cavity quantum electrodynamics for arbitrary geometry of boundaries. This Hamiltonian is free from the A-square term and the instantaneous Coulomb interaction between distinct atoms. The single-mode models of ...

[Phys. Rev. Lett. 112, 073601] Published Thu Feb 20, 2014

]]>The ionization dynamics of He nanodroplets irradiated with intense femtosecond extreme ultraviolet pulses of up to 1013 W/cm2 power density have been investigated by photoelectron spectroscopy. Helium droplets were resonantly excited to atomiclike 2p states with a photon energy of 21.4 eV, below th...

[Phys. Rev. Lett. 112, 073401] Published Thu Feb 20, 2014

]]>We discuss the dc conductivity of holographic theories with translational invariance broken by a background lattice. We show that the presence of the lattice induces an effective mass for the graviton via a gravitational version of the Higgs mechanism. This allows us to obtain, at leading order in t...

[Phys. Rev. Lett. 112, 071602] Published Thu Feb 20, 2014

]]>We investigate theoretically the suppression of two-body losses when the on-site loss rate is larger than all other energy scales in a lattice. This work quantitatively explains the recently observed suppression of chemical reactions between two rotational states of fermionic KRb molecules confined ...

[Phys. Rev. Lett. 112, 070404] Published Thu Feb 20, 2014

]]>The proximity of the Fermi surface to van Hove singularities drastically enhances interaction effects and leads to essentially new physics. In this work we address the formation of flat bands (“Fermi condensation”) within the Hubbard model on the triangular lattice and provide a detailed analysis fr...

[Phys. Rev. Lett. 112, 070403] Published Thu Feb 20, 2014

]]>We study a hybrid system formed from an optomechanical resonator and a cavity mode strongly coupled to an excitonic transition inside a quantum well. We show that due to the mixing of cavity photon and exciton states, the emergent quasiparticles—polaritons—possess coupling to the mechanical mode of ...

[Phys. Rev. Lett. 112, 076402] Published Wed Feb 19, 2014

]]>Squeezed vacuum states constitute a particularly useful resource in quantum information as well as in quantum metrology. The frequency conversion of these states is important to provide the bridge between different wavelengths within a sequence of downstream applications and also to provide a way fo...

[Phys. Rev. Lett. 112, 073602] Published Wed Feb 19, 2014

]]>We report an observation of long-lived spin-singlet states in a C-H113 spin pair in a zero magnetic field. In C13-labeled formic acid, we observe spin-singlet lifetimes as long as 37 s, about a factor of 3 longer than the T1 lifetime of dipole polarization in the triplet state. In contrast to comm...

[Phys. Rev. Lett. 112, 077601] Published Tue Feb 18, 2014

]]>Penning ionization initiates the evolution of a dense molecular Rydberg gas to plasma. This process selects for pairs of excited molecules separated by a distance of two Rydberg orbital diameters or less. The deactivated Penning partners predissociate, depleting the leading edge of the distribution ...

[Phys. Rev. Lett. 112, 075001] Published Tue Feb 18, 2014

]]>We investigate how natural curvature affects the configuration of a thin elastic rod suspended under its own weight, as when a single strand of hair hangs under gravity. We combine precision desktop experiments, numerics, and theoretical analysis to explore the equilibrium shapes set by the coupled ...

[Phys. Rev. Lett. 112, 068103] Published Thu Feb 13, 2014

]]>We propose a simple system of optically driven colloids that convert light into heat and move in response to self-generated and collectively generated thermal gradients. We show that the system exhibits self-organization into a moving cometlike swarm and characterize the structure and response of th...

[Phys. Rev. Lett. 112, 068302] Published Wed Feb 12, 2014

]]>We present transport measurements of cleaved edge overgrowth GaAs quantum wires. The conductance of the first mode reaches 2e2/h at high temperatures T≳10 K, as expected. As T is lowered, the conductance is gradually reduced to 1e2/h, becoming T independent at T≲0.1 K, while the device cools far b...

[Phys. Rev. Lett. 112, 066801] Published Mon Feb 10, 2014

]]>The T2K experiment has observed electron neutrino appearance in a muon neutrino beam produced 295 km from the Super-Kamiokande detector with a peak energy of 0.6 GeV. A total of 28 electron neutrino events were detected with an energy distribution consistent with an appearance signal, corresponding ...

[Phys. Rev. Lett. 112, 061802] Published Mon Feb 10, 2014

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