Lead-free, potassium sodium niobate piezoelectric ceramics substituted with lithium (K0.5−x∕2,Na0.5−x∕2,Lix)NbO3 or and tantalum (K0.5−x∕2,Na0.5−x∕2,Lix)(Nb1−y,Tay)O3 have been synthesized by traditional solid state sintering. The compositions chosen are among those recently reported to show high properties [Y. Saito, H. Takao, T. Tani, Nonoyama, K. Takatori, Homma, Nagaya, M. Nakamura, Nature (London) 42, 84 (2004); Y. Guo, Kakimoto, Ohsato, Appl. Phys. Lett. 85, 4121 Mater. 59, 241...

We review phase-space techniques based on the Wigner representation that provide an approximate description of dilute ultra-cold Bose gases. In this approach quantum field evolution can be represented using equations motion a similar form to Gross–Pitaevskii equation but with stochastic modifications include effects in controlled degree approximation. These practical quantitative both equilibrium and dynamical properties gas systems. develop versions formalism appropriate at zero...

We report experimental observations and numerical simulations of the formation, dynamics, lifetimes single multiply charged quantized vortex dipoles in highly oblate dilute-gas Bose-Einstein condensates (BECs). nucleate pairs vortices opposite charge (vortex dipoles) by forcing superfluid flow around a repulsive gaussian obstacle within BEC. By controlling velocity we determine critical for nucleation dipole, with excellent agreement between results. present measurements dipole finding that...

Adding energy to a system through transient stirring usually leads more disorder. In contrast, point-like vortices in bounded two-dimensional fluid are predicted reorder above certain energy, forming persistent vortex clusters. Here we realize experimentally these clusters planar superfluid: $^{87}$Rb Bose-Einstein condensate confined an elliptical geometry. We demonstrate that the persist for long times, maintaining superfluid high state far from global equilibrium. Our experiments explore...

Electric-field-induced phase transitions have been evidenced by macroscopic strain measurements at temperatures between $25\phantom{\rule{0.2em}{0ex}}\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$ and $100\phantom{\rule{0.2em}{0ex}}\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$ in ${[001]}_{C}$-poled...

The importance of a high shear coefficient d15 (or d24) to the piezoelectric properties domain-engineered and polycrystalline ferroelectrics is discussed. extent polarization rotation, as mechanism response, directly correlated coefficient. terms “rotator” “extender” are introduced distinguish contrasting behaviors crystals such 4mm BaTiO3 PbTiO3. In rotator ferroelectrics, where relative longitudinal d33, rotation dominant response; maximum response found away from polar axis. extender low...

We introduce a time-dependent projected Gross-Pitaevskii equation to describe partially condensed homogeneous Bose gas, and find that this will evolve randomized initial wave functions equilibrium. compare our numerical data the predictions of gapless, second order theory Bose-Einstein condensation [S. A. Morgan, J. Phys. B 33, 3847 (2000)], we can determine temperature when is valid. As nonperturbative, expect it correct thermal behavior gas as long all relevant modes are highly occupied....

A parameter whose coupling to a quantum probe of $n$ constituents includes all two-body interactions between the can be measured with an uncertainty that scales as $1/{n}^{3/2}$, even when are initially unentangled. We devise protocol achieves $1/{n}^{3/2}$ scaling without generating any entanglement among constituents, and we suggest might implemented in two-component Bose-Einstein condensate.

Fluids subjected to suitable forcing will exhibit turbulence, with characteristics strongly affected by the fluid's physical properties and dimensionality. In this work, we explore two-dimensional (2D) quantum turbulence in an oblate Bose-Einstein condensate confined annular trapping potential. Experimentally, find conditions for which small-scale stirring of generates disordered 2D vortex distributions that dissipatively evolve toward persistent currents, indicating energy transport from...

We investigate a spin-orbit-coupled Bose-Einstein condensate loaded into translating optical lattice. experimentally demonstrate the lack of Galilean invariance in system, which leads to anisotropic behavior depending on direction translation The anisotropy is theoretically understood by an effective dispersion relation. confirm this theoretical picture probing dynamical instability system.

We study the relaxation dynamics of an isolated zero temperature quasi-two-dimensional superfluid Bose-Einstein condensate that is imprinted with a spatially random distribution quantum vortices. Following period vortex annihilation remaining vortices self-organize into two macroscopic coherent "Onsager vortex" clusters are stable indefinitely--despite absence driving or external dissipation in dynamics. demonstrate this occurs due to novel physical mechanism--the evaporative heating...

Programable spatial light modulators (SLMs) have significantly advanced the configurable optical trapping of particles. Typically, these devices are utilized in Fourier plane an system, but direct imaging amplitude pattern can potentially result increased simplicity and computational speed. Here we demonstrate high-resolution a digital micromirror device (DMD) at high numerical apertures (NA), which apply to Bose-Einstein condensate (BEC). We utilise (1200 x 1920) pixel DMD commercially...

We show that ferromagnetic interactions can enhance the adiabatic performance of a quantum spin chain engine at low temperatures. The enhancement in work output is particular pronounced, increasing exponentially with interaction strength. occurs paramagnetic phase and qualitatively explained by considering just ground first excited state, which case system exhibits bipartite entanglement. As temperature increased, thermal occupation higher energy states diminishes performance. find these...

The formation process of a Bose-Einstein condensate in trap is described using master equation based on quantum kinetic theory, which can be well approximated by description only the mode interaction with thermalized bath noncondensate atoms. A rate form n = 2W(n)[(1-exp((mu_n - mu)/kT))n + 1] derived, difference between chemical potential mu_n and mu gives essential behavior. Solutions this equation, conjunction theoretical evaporative cooling, give characteristic latency period for appear...

The miscibility-immiscibility phase transition in binary Bose-Einstein condensates (BECs) can be controlled by a coupling between the two components. Here we propose new scheme that uses coupling-induced pattern formation to test Kibble-Zurek mechanism (KZM) of topological-defect quantum transition. For BEC ring trap find number domains forming scales with quench rate an exponent as predicted KZM. elongated harmonic different scaling law due being spatially inhomogeneous. We perform...

We develop a stochastic Gross-Pitaveskii theory suitable for the study of Bose-Einstein condensation in rotating dilute Bose gas. The is used to model dynamical and equilibrium properties rapidly gas quenched through critical point condensation, as experiment Haljan et al. [Phys. Rev. Lett. 87, 210403 (2001)]. In contrast stirring vortex-free condensate, where topological constraints require that vortices enter from edge we find phase defects initial noncondensed cloud are trapped en masse...

We demonstrate the role of interactions in driving relaxation an isolated integrable quantum system following a sudden quench. consider family hard-core lattice anyon models that continuously interpolates between noninteracting spinless fermions and strongly interacting bosons. A generalized Jordan-Wigner transformation maps entire to fermions. find that, aside from singular free-fermion limit, single-particle density matrix therefore all one-body observables relax predictions Gibbs ensemble...

In a major extension of our previous model [Phys. Rev. Lett. 79, 1793 (1997)] condensate growth, we take account the evolution occupations lower trap levels, and full Bose-Einstein formula for higher levels. We find good agreement with experiment, especially at temperatures. also confirm picture ``kinetic'' region evolution, introduced by Kagan et al., time up to initiation condensate. The behavior after essentially follows original growth equation, but substantially increased rate...

A large bis-urea macrocycle was synthesized and assembled into columnar nanotubes containing a sizable cavity. This purely organic nanotube is held together primarily by hydrogen bonding yet shows remarkable thermal stability up to 180 degrees C in the presence absence of acetic acid guest. enables be used as reusable zeolite.

We provide a derivation of more accurate version the stochastic Gross-Pitaevskii equation, as introduced by Gardiner et al. (J. Phys. B 35,1555,(2002). The does not rely on concept local energy and momentum conservation, is based quasi-classical Wigner function representation "high temperature" master equation for Bose gas, which includes only modes below an cutoff E_R that are sufficiently highly occupied (the condensate band). above this non-condensate band) treated being essentially...

The transverse piezoelectric coefficient d31⋆ has been calculated for the six domain-engineered structures occurring in perovskite single crystals, using data rhombohedral PMN-33PT [0.67Pb(Mg1∕3Nb2∕3)O3-0.33PbTiO3], orthorhombic potassium niobate (KNbO3), tetragonal barium titanate (BaTiO3), and lead (PbTiO3). Unlike longitudinal (d33⋆), is found to be strongly dependent on (x1′) direction of as-cut crystal. In general, different domains a structure will contribute values that measured....

Using recently published experimental data we calculated the piezoelectric response of rhombohedral 0.67Pb(Mg1/3Nb2/3)O3–0.33PbTiO3 monodomain single crystals along arbitrary directions. The calculations indicate that value longitudinal coefficient [001] axis pseudocubic system ([111] system) a crystal is close to determined experimentally same direction multidomain with so-called “engineered domain state.” results thus show large in this material dominated by intrinsic lattice effects and...