In the presence of a laser-induced spin-orbit coupling an interacting ultracold spinor Bose-Einstein condensate may acquire quasirelativistic character described by nonlinear Dirac-like equation. We show that as result and nonlinearity become self-trapped, resembling so-called chiral confinement, previously studied in context massive Thirring model. first consider 1D geometries where self-confined condensates present intriguing sinusoidal dependence on interparticle interactions. further...

Ultracold atoms which are subject to ultra-relativistic dynamics investigated. By using optically induced gauge potentials we show that the of is governed by a Dirac-type equation. To illustrate this study trembling motion centre mass for an effective two-level system, historically called Zitterbewegung. Its origin described in detail, where particular role finite width atomic wave packets seen induce damping both and populations two levels.

We present a general scheme to determine the loss-free adiabatic eigensolutions (dark-state polaritons) of interaction multiple probe laser beams with coherently driven atomic ensemble under conditions electromagnetically induced transparency. To this end we generalize Morris-Shore transformation linearized Heisenberg-Langevin equations describing coupled light-matter system in weak excitation limit. For simple lambda-type coupling generalized reproduces dark-state polariton solutions slow...

The advantages of light and matter-wave Sagnac interferometers---large area on one hand high rotational sensitivity per unit the other---can be combined utilizing ultraslow in cold atomic gases. While a group-velocity reduction alone does not affect phase shift, associated momentum transfer from to atoms generates coherent component which gives rise substantially enhanced signal. It is shown that large-area interferometer can achieved if an optically dense vapor at subrecoil temperatures...

For high electric fields, the lifetime of Wannier-Stark ladder states in a periodic potential is reduced by fundamental process Zener tunneling. We report on analysis coherence such semiconductor superlattices interband spectroscopy. The reduction strong coupling between bands can only first approximation be described well-known theory. A recently developed theoretical model applied to calculate directly tunneling probability as function field. results compare well with experiment,...

We propose a scheme to entangle two mechanical nanocantilevers through indirect interactions mediated by gas of ultracold atoms. envisage system magnetically coupled Bose-Einstein condensate atoms and focus on studying the dark states system. These are entangled nanocantilevers, with no coupling atomic condensate. In absence dissipation, degree entanglement is found oscillate time, while if dissipation included, relax statistical mixture which remains time independent until inevitable...

The paramagnetic behavior of 18-electron cyclopentadienylnickel(II) complexes the [CpNi(μ-Br)]2 type with two unpaired electrons per metal ion has been investigated by 1H and 13C NMR spectroscopy [Cp‴Ni(μ-Br)]2 (1; Cp‴ = 1,3,4-tBu3C5H2), [3CpNi(μ-Br)]2 (2; 3Cp 1,3,4-iPr3C5H2), [4CpNi(μ-Br)]2 (3; 4Cp 2,3,4,5-iPr4C5H). tri-tert-butylcyclopentadienyl derivative 1 crystallizes in triclinic space group P1̅ X-ray crystallography. Solid-state magnetic susceptibility measurements 3 revealed an...

Wannier-Stark states for semiconductor superlattices in strong static fields, where the interband Landau-Zener tunneling cannot be neglected, are rigorously calculated. The lifetime of these metastable was found to show multiscale oscillations as a function field, which is explained by an interaction with above-barrier resonances. An equation, expressing absorption spectrum terms resonance states, obtained and used calculate region high fields.

For harmonic-trapped atomic systems, we report system-independent nonadiabatic features in the response to interaction ramps. We provide results for several different systems one, two, and three dimensions: bosonic fermionic Hubbard models realized through optical lattices, a Bose-Einstein condensate, superfluid, Fermi liquid. The deviation from adiabaticity is characterized heating or excitation energy produced during ramp. find that dependence of heat on ramp time sensitive protocol but...

The light-matter-wave Sagnac interferometer based on ultraslow light proposed recently in Zimmer and Fleischhauer, Phys. Rev. Lett. 92, 253201 (2004), is analyzed detail. In particular the effect of confining potentials examined it shown that attains a rotational phase shift equivalent to matter wave, if only coherence transfer from atoms associated with slow momentum an ultracold gas ring trap used. quantum sensitivity limit determined minimum detectable rotation rate calculated. It...

We put forth and discuss in detail a scheme to achieve Bose-Einstein condensation of stationary-light dark-state polaritons with dipolar interaction. To this end we introduce diamondlike coupling vapor Rydberg atoms under the frozen gas approximation. determine system's dynamics employ normal modes identify polariton corresponding one modes. show that contrast atomic ultracold vapors, condensates proposed here can be stable for negative interaction constant.

We report the observation of transient velocity-selective coherent population trapping (VSCPT) in a beam metastable neon atoms. The atomic momentum distribution resulting from interaction with counterpropagating sigma_+ and sigma_- radiation which couples J_g=2 J_e=1 transition is measured via transversal profile. This exhibits stable VSCPT dark state formed by two |J=2,m=+/-1> states, containing |J=2,m=+/-2> |J=2,m=0> states. dynamics formation decay states studied experimentally...