其他凝聚态物理
A two-dimensional system of atoms in an anisotropic optical lattice is studied theoretically. If the system is finite in one direction, it is shown to exhibit a transition between a two-dimensional superfluid and a one-dimensional Mott…
Partial sum rules are widely used in physics to separate low- and high-energy degrees of freedom of complex dynamical systems. Their application, though, is challenged in practice by the always finite spectrometer bandwidth and is often…
We report on size-dependent properties of dithallium selenide, Tl2Se. We have carried out a comparative nuclear magnetic resonance (NMR) study of Tl2Se nanorods and bulk samples, measuring NMR spectra and spin-lattice relaxation rate of…
We calculate the bound plasmonic modes of a quantum metamaterial slab, comprised of multiple quasi two dimensional electron gas (Q2DEG) layers, whose thickness is much smaller than the optical wavelength. For the first order transverse…
Intersubband response in a superlattice subjected to a homogeneous electric field (biased superlattice with equipopulated levels) is studied within the tight-binding approximation, taking into account the interplay between homogeneous and…
We extend recently proposed variational coupled-cluster method to describe excitation states of quantum many-body interacting systems. We discuss, in general terms, both quasiparticle excitations and quasiparticle-density-wave excitations…
We show that $N-1$ degenerate dark states can be generated by coupling $N$-fold degenerate ground states and a common excited state with $N$ laser fields. Interferences between light waves with different frequencies can produce laser fields…
We observe unidirectional charge density wave ordering on the cleaved surface of TbTe3 with a Scanning Tunneling Microscope at ~6 K. The modulation wave-vector q_{CDW} as determined by Fourier analysis is 0.71 +/- 0.02 * 2 pi/c. (Where c is…
Coherent optical information storage capacity of an atomic Bose-Einstein condensate is examined. Theory of slow light propagation in atomic clouds is generalized to short pulse regime by taking into account group velocity dispersion. It is…
We demonstrate the existence of Bloch oscillations of acoustic fields in sound propagation through a superlattice of water cavities and layers of methyl methacrylate. To obtain the acoustic equivalent of a Wannier-Stark ladder, we have…
We study propagation of short laser pulses in a Bose-Einstein condensate taking into account dispersive effects under the conditions for electromagnetically induced transparency. We calculate dispersion coefficients using typical…
We investigate the dynamics of Na clusters embedded in Ar matrices. We use a hierarchical approach, accounting microscopically for the cluster's degrees of freedom and more coarsely for the matrix. The dynamical polarizability of the Ar…
Expansion of a Bose-Einstein condensate (BEC) is studied, in the presence of a random potential. The expansion is controlled by a single parameter, $(\mu\tau_{eff} /\hbar)$, where $\mu$ is the chemical potential, prior to the release of the…
We study the ground state properties of repulsively interacting bosons on the honeycomb lattice using large-scale quantum Monte Carlo simulations. In the hard-core limit the half-filled system develops long ranged diagonal order for…
We study the superfluid phases of quasi-2D atomic Fermi gases interacting via a p-wave Feshbach resonance. We calculate the absorption spectra of these phases under a hyperfine transition, for both non-rotating and rotating superfluids. We…
We investigate waveguiding of ultraslow light pulses in an atomic Bose-Einstein condensate. We show that under the conditions of off-resonant electromagnetically induced transparency, waveguiding with a few ultraslow modes can be realized.…
We report an experimental study of miniband magnetoconduction in semiconducting InAs/GaSb superlattices. For samples with miniband widths below the longitudinal optical phonon energy we identify a new superlattice magnetophonon resonance…
Two-component Bose-Einstein condensates are considered within a number conserving version of the Bogoliubov theory. We show that the Bogoliubov vacuum state can be obtained in the particle representation in a simple form. We predict…
20 years ago a new quantum state of matter was discovered and identified. The observed dynamic quantum state of spin precession in superfluid 3He-B bears the properties of spin current superfluidity, Bose condensation of spin waves --…
People have been familiar with the phenomenon of wave refraction for several centuries. Recently, a novel type of refraction, i.e., negative refraction, where both incident and refractory lines locate on the same side of the normal line,…