We present evidence of the gravitational lensing of the cosmic microwave background by ${10}^{13}$ solar mass dark matter halos. Lensing convergence maps from the Atacama Cosmology Telescope Polarimeter (ACTPol) are stacked at the positions of around 12 000 optically selected CMASS galaxies from the SDSS-III/BOSS survey. The mean lensing signal is consistent with simulated dark matter halo profiles and is favored over a null signal at $3.2\sigma$ significance. This result demonstrates the potential of microwave background lensing to probe the dark matter distribution in galaxy group and galaxy cluster halos.

We study the rectification of voltage fluctuations in a system consisting of two Coulomb-coupled quantum dots. The first quantum dot is connected to a reservoir where voltage fluctuations are supplied and the second one is attached to two separate leads via asymmetric and energy-dependent transport barriers. We observe a rectified output current through the second quantum dot depending quadratically on the noise amplitude supplied to the other Coulomb-coupled quantum dot. The current magnitude and direction can be switched by external gates, and maximum output currents are found in the nA region. The rectification delivers output powers in the pW region. Future devices derived from our sample may be applied for energy harvesting on the nanoscale beneficial for autonomous and energy-efficient electronic applications.

Tune-out wavelengths measured with an atom interferometer are sensitive to laboratory rotation rates because of the Sagnac effect, vector polarizability, and dispersion compensation. We observed shifts in measured tune-out wavelengths as large as 213 pm with a potassium atom beam interferometer, and we explore how these shifts can be used for an atom interferometer gyroscope.

We investigate low temperature grown, abrupt, epitaxial, nonintermixed, defect-free $n$-type and $p$-type $\mathrm{Fe}/\mathrm{GaAs}(110)$ interfaces by cross-sectional scanning tunneling microscopy and spectroscopy with atomic resolution. The probed local density of states shows that a model of the ideal metal-semiconductor interface requires a combination of metal-induced gap states and bond polarization at the interface which is nicely corroborated by density functional calculations. A three-dimensional finite element model of the space charge region yields a precise value for the Schottky barrier height.

Using a matter wave lens and a long time of flight, we cool an ensemble of ${}^{87}\mathrm{Rb}$ atoms in two dimensions to an effective temperature of less than $50_{-30}^{+50}\mathrm{pK}$. A short pulse of red-detuned light generates an optical dipole force that collimates the ensemble. We also report a three-dimensional magnetic lens that substantially reduces the chemical potential of evaporatively cooled ensembles with a high atom number. By observing such low temperatures, we set limits on proposed modifications to quantum mechanics in the macroscopic regime. These cooling techniques yield bright, collimated sources for precision atom interferometry.

A counterintuitive, thermocapillary-induced limit to heat- pipe performance was observed that is not predicted by current thermal-fluid models. Heat pipes operate under a number of physical constraints including the capillary, boiling, sonic, and entrainment limits that fundamentally affect their performance. Temperature gradients near the heated end may be high enough to generate significant Marangoni forces that oppose the return flow of liquid from the cold end. These forces are believed to exacerbate dry out conditions and force the capillary limit to be reached prematurely. Using a combination of image and thermal data from experiments conducted on the International Space Station with a transparent heat pipe, we show that in the presence of significant Marangoni forces, dry out is not the initial mechanism limiting performance, but that the physical cause is exactly the opposite behavior: flooding of the hot end with liquid. The observed effect is a consequence of the competition between capillary and Marangoni-induced forces. The temperature signature of flooding is virtually identical to dry out, making diagnosis difficult without direct visual observation of the vapor-liquid interface.

Super-Kamiokande (SK) can search for weakly interacting massive particles (WIMPs) by detecting neutrinos produced from WIMP annihilations occurring inside the Sun. In this analysis, we include neutrino events with interaction vertices in the detector in addition to upward-going muons produced in the surrounding rock. Compared to the previous result, which used the upward-going muons only, the signal acceptances for light ($\text{few}\text{−}\mathrm{GeV}/c^2\text{−}200\text{−}\mathrm{GeV}/c^2$) WIMPs are significantly increased. We fit 3903 days of SK data to search for the contribution of neutrinos from WIMP annihilation in the Sun. We found no significant excess over expected atmospheric-neutrino background and the result is interpreted in terms of upper limits on WIMP-nucleon elastic scattering cross sections under different assumptions about the annihilation channel. We set the current best limits on the spin-dependent WIMP-proton cross section for WIMP masses below $200\mathrm{GeV}/c^2$ (at $10\mathrm{GeV}/c^2$, $1.49\times {10}^{-39}{\mathrm{cm}}^2$ for $\chi \chi \to b\overline{b}$ and $1.31\times {10}^{-40}{\mathrm{cm}}^2$ for $\chi \chi \to {\tau }^{+}{\tau }^{-}$ annihilation channels), also ruling out some fraction of WIMP candidates with spin-independent coupling in the $\text{few}\text{−}\mathrm{GeV}/c^2$ mass range.

Excitation functions for the Gaussian emission source radii difference ($R_{\text{out}}^2-R_{\text{side}}^2$) obtained from two-pion interferometry measurements in $\mathrm{Au}+\mathrm{Au}$ ($\sqrt{s_{NN}}=7.7–200\mathrm{GeV}$) and $\mathrm{Pb}+\mathrm{Pb}$ ($\sqrt{s_{NN}}=2.76\mathrm{TeV}$) collisions are studied for a broad range of collision centralities. The observed nonmonotonic excitation functions validate the finite-size scaling patterns expected for the deconfinement phase transition and the critical end point (CEP), in the temperature versus baryon chemical potential ($T,{\mu }_B$) plane of the nuclear matter phase diagram. A finite-size scaling (FSS) analysis of these data suggests a second order phase transition with the estimates $T^{\mathrm{cep}}\sim 165\mathrm{MeV}$ and ${\mu }_B^{\mathrm{cep}}\sim 95\mathrm{MeV}$ for the location of the critical end point. The critical exponents ($\nu \approx 0.66$ and $\gamma \approx 1.2$) extracted via the same FSS analysis place this CEP in the 3D Ising model universality class.

We use a novel electrostatic ion storage ring to measure the radiative lifetime of the upper level in the $3p^5{{}^{2}P}_{1/2}^o\to 3p^5{{}^{2}P}_{3/2}^o$ spontaneous radiative decay in ${}^{32}{\mathrm{S}}^{-}$ to be $503\pm 54\sec$. This is by orders of magnitude the longest lifetime ever measured in a negatively charged ion. Cryogenic cooling of the storage ring gives a residual-gas pressure of a few times ${10}^{-14}$ mbar at 13 K and storage of 10 keV sulfur anions for more than an hour. Our experimental results differ by $1.3\sigma$ from the only available theoretical prediction [P. Andersson et al., Phys. Rev. A 73, 032705 (2006)].

We report a laboratory investigation of weak turbulence of water surface waves in the gravity-capillary crossover. By using time-space-resolved profilometry and a bicoherence analysis, we observe that the nonlinear processes involve three-wave resonant interactions. By studying the solutions of the resonance conditions, we show that the nonlinear interaction is dominantly one dimensional and involves collinear wave vectors. Furthermore, taking into account the spectral widening due to weak nonlinearity explains why nonlocal interactions are possible between a gravity wave and high-frequency capillary ones. We observe also that nonlinear three-wave coupling is possible among gravity waves, and we raise the question of the relevance of this mechanism for oceanic waves.

This Letter reports the first experimental investigation into a line-tied plasma with a reversed current profile. Discrete current sources create a cylindrical plasma equilibrium with an axial field and zero net current. Detailed magnetic measurements show that an internal $m=1$ mode with no external character grows exponentially. The nonlinear evolution of the mode drives 3D reconnection events that reorganize the plasma equilibrium. The plasma is turbulent and exhibits reconnection events on a range of scales. These data are consistent with recent simulations of coronal loops and the nanoflare coronal heating mechanism.

We demonstrate that $E\times B$ shear, $V_{E\times B}^{\prime }$, governs the dynamics of the cross phase of the peeling-ballooning-(PB-)mode-driven heat flux, and so determines the evolution from the edge-localized (ELMy) $H$ mode to the quiescent ($Q$) $H$ mode. A physics-based scaling of the critical $E\times B$ shearing rate ($V_{E\times B,cr}^{\prime }$) for accessing the $QH$ mode is predicted. The ELMy $H$ mode to the $QH$-mode evolution is shown to follow from the conversion from a phase locked state to a phase slip state. In the phase locked state, PB modes are pumped continuously, so bursts occur. In the slip state, the PB activity is a coherent oscillation. Stronger $E\times B$ shearing implies a higher phase slip frequency. This finding predicts a new state of cross phase dynamics and shows a new way to understand the physics mechanism for ELMy to the $QH$-mode evolution.

We report measurements of the correlations between electromagnetic field quadratures at two frequencies $f_1=7\mathrm{GHz}$ and $f_1=7.5\mathrm{GHz}$ of the radiation emitted by a tunnel junction placed at very low temperature and excited at frequency $f_1+f_2$. We demonstrate the existence of two-mode squeezing and violation of a Bell-like inequality, thereby proving the existence of entanglement in the quantum shot noise radiated by the tunnel junction.

In the presence of nonadsorbing polymers, colloidal particles experience ubiquitous attractive interactions induced by depletion forces. Here, we measure the depletion interaction between a pair of microtubule filaments using a method that combines single filament imaging with optical trapping. By quantifying the dependence of filament cohesion on both polymer concentration and solution ionic strength, we demonstrate that the minimal model of depletion, based on the Asakura-Oosawa theory, fails to quantitatively describe the experimental data. By measuring the cohesion strength in two- and three- filament bundles, we verify pairwise additivity of depletion interactions for the specific experimental conditions. The described experimental technique can be used to measure pairwise interactions between various biological or synthetic filaments and complements information extracted from bulk osmotic stress experiments.

For almost 50 years the structure of the $\mathrm{\Lambda }(1405)$ resonance has been a mystery. Even though it contains a heavy strange quark and has odd parity, its mass is lower than any other excited spin-$1/2$ baryon. Dalitz and co-workers speculated that it might be a molecular state of an antikaon bound to a nucleon. However, a standard quark-model structure is also admissible. Although the intervening years have seen considerable effort, there has been no convincing resolution. Here we present a new lattice QCD simulation showing that the strange magnetic form factor of the $\mathrm{\Lambda }(1405)$ vanishes, signaling the formation of an antikaon-nucleon molecule. Together with a Hamiltonian effective-field-theory model analysis of the lattice QCD energy levels, this strongly suggests that the structure is dominated by a bound antikaon-nucleon component. This result clarifies that not all states occurring in nature can be described within a simple quark model framework and points to the existence of exotic molecular meson-nucleon bound states.

Biological patterns generated during development and regeneration often scale with organism size. Some organisms, e.g., flatworms, can regenerate a rescaled body plan from tissue fragments of varying sizes. Inspired by these examples, we introduce a generalization of Turing patterns that is self-organized and self-scaling. A feedback loop involving diffusing expander molecules regulates the reaction rates of a Turing system, thereby adjusting pattern length scales proportional to system size. Our model captures essential features of body plan regeneration in flatworms as observed in experiments.

We have explored the origin of unusual first-order-type electronic and structural transitions in ${\mathrm{IrTe}}_2$, based on the first-principles total energy density functional theory analysis. We have clarified that the structural transition occurs through the interplay among the charge density wavelike lattice modulation with $q_{1/5}=(1/5,0,1/5)$, in-plane dimer ordering, and the uniform lattice deformation. The Ir-Ir dimer formation via a molecular-orbital version of the Jahn-Teller distortion in the Ir-Ir zigzag stripe is found to play the most important role in producing the charge disproportionation state. Angle-resolved photoemission spectroscopy reveals the characteristic features of structural transition, which are in good agreement with the density functional theory bands obtained by the band-unfolding technique.

Efficient readout of individual electronic spins associated with atomlike impurities in the solid state is essential for applications in quantum information processing and quantum metrology. We demonstrate a new method for efficient spin readout of nitrogen-vacancy (NV) centers in diamond. The method is based on conversion of the electronic spin state of the NV to a charge-state distribution, followed by single-shot readout of the charge state. Conversion is achieved through a spin-dependent photoionization process in diamond at room temperature. Using NVs in nanofabricated diamond beams, we demonstrate that the resulting spin readout noise is within a factor of 3 of the spin projection noise level. Applications of this technique for nanoscale magnetic sensing are discussed.

We propose and analyze a scheme for parametrically cooling bilayer cuprates based on the selective driving of a $c$-axis vibrational mode. The scheme exploits the vibration as a transducer making the Josephson plasma frequencies time dependent. We show how modulation at the difference frequency between the intrabilayer and interbilayer plasmon substantially suppresses interbilayer phase fluctuations, responsible for switching $c$-axis transport from a superconducting to a resistive state. Our calculations indicate that this may provide a viable mechanism for stabilizing nonequilibrium superconductivity even above $T_c$, provided a finite pair density survives between the bilayers out of equilibrium.

We demonstrate a new method to realize the population inversion of a single $\mathrm{InGaAs}/\mathrm{GaAs}$ quantum dot excited by a laser pulse tuned within the neutral exciton phonon sideband. In contrast to the conventional method of inverting a two-level system by performing coherent Rabi oscillation, the inversion is achieved by rapid thermalization of the optically dressed states via incoherent phonon-assisted relaxation. A maximum exciton population of $0.67\pm 0.06$ is measured for a laser tuned 0.83 meV to higher energy. Furthermore, the phonon sideband is mapped using a two-color pump-probe technique, with its spectral form and magnitude in very good agreement with the result of path-integral calculations.