Related papers: Classical Rotons in Cold Atomic Traps
The elementary optical excitations of a two-dimensional electron system strongly coupled to a microcavity are trion-polaritons. Using a variational approach, we demonstrate that the competition between Coulomb interaction and light-matter…
Amontons' law postulates a monotonic relationship between frictional force and the normal load applied to a sliding contact. This empirical rule, however, fails in systems where internal degrees of freedom - such as structural or electronic…
Roton excitations constitute a key feature of dipolar gases, connecting these gases with superfluid helium. We show that the density dependence of the roton minimum results in a spatial roton confinement, particularly relevant in pancake…
We point out the possibility of having a roton-type excitation spectrum in a quasi-1D Bose-Einstein condensate with dipole-dipole interactions. Normally such a system is quite unstable due to the attractive portion of the dipolar…
Clouds of cold neutral atoms driven by a coherent light beam in a ring cavity exhibit self-structured states transversely with respect to the beam axis due to optomechanical forces and the back action of the atomic structures on the beam.…
We consider effective interactions in a 2D hybrid polariton- electron system and calculate dispersion of elementary excitations accounting the spin degree of freedom of the particles. Due to the crucial role played by the exchange term in…
We propose a scheme involving cold atoms trapped in optical lattices to observe different phenomena traditionally linked to quantum-optical systems. The basic idea consists of connecting the trapped atomic state to a non-trapped state…
We introduce and analyze a model for the transport of particles or energy in extended lattice systems. The dynamics of the model acts on a discrete phase space at discrete times but has nonetheless some of the characteristic properties of…
In this paper we continue the investigation of the lattice gas model. The main improvement is that we use two strengths for bonds: one between like particles and another between unlike particle to implement the isospin-dependence of nuclear…
Cold atomic gases resonantly excited to Rydberg states can exhibit strong optical nonlinearity at the single photon level. We observe that in such samples radiation trapping leads to an additional mechanism for Rydberg excitation.…
Quantum lattice systems are rigorously studied at low temperatures. When the Hamiltonian of the system consists of a potential (diagonal) term and a - small - off-diagonal matrix containing typically quantum effects, such as a hopping…
We study long-range interacting electrons on the triangular lattice using mixed quantum/classical simulations going beyond the usual classical descriptions of the lattice Coulomb fluid. Our results in the strong interaction limit indicate…
Rotons can exist in ultracold atomic gases either with long-range interactions or with spin-orbitcoupled dispersions. We find that two different kinds of rotons coexist in a joint system combining long-range interactions and spin-orbit…
We present a theoretical model describing recently observed collective effects in large magneto-optically trapped atomic ensembles. Based on a kinetic description we develop an efficient test particle method, which in addition to the single…
A key concept proposed by Landau to explain superfluid liquid helium is the elementary excitation of quantum particles called rotons. The irregular arrangement of atoms in a liquid forms the aperiodic dispersion of rotons that played a…
We present a perturbative study of the response of cold atoms in an optical lattice to a weak time- and space-asymmetric periodic driving signal. In the noninteracting limit, and for a finite set of resonant frequencies, we show how a…
When two of three pairs of the Gaussian laser beams of a traditional MOT are misaligned in the racetrack configuration the effective coordinate-dependent vortex force do arise. Then an atom is accelerated by this vortex force until its…
The effect of long-ranged Coulomb interaction on the low energy properties (momentum distribution function, density of states, electron spectral function, and $4k_F$ correlation function) of one-dimensional electron systems is determined…
We present measurements and calculations of the trap loss rate for laser cooled Rb atoms confined in either a magneto-optic or a magnetic quadrupole trap when exposed to a room temperature background gas of Ar. We study the loss rate as a…
Orientational fluctuations of colloidal particles with magnetic moments may be rectified with the help of external magnetic fields with suitably chosen time dependence. As a result a noise-driven rotation of particles occurs giving rise to…