Gravitational atoms

Gravitational field measurement with an equilibrium ensemble of cold atoms

A new approach to the measurement of gravitational fields with an equilibrium ensemble of ultra-cold alkali atoms confined in a cell of volume V is investigated. The proposed model of the gravitational sensor is based on a variation of the density profile of the ensemble due to changing of the gravitational field. For measurement the atomic density variations of the ensemble the electromagnetic...

Dipole coupling of atoms and light in gravitational fields.

The dipole coupling term between a system of N particles with total charge zero and the electromagnetic field is derived in the presence of a weak gravitational field. It is shown that the form of the coupling remains the same as in flat space-time if it is written with respect to the proper time of the observer and to the measurable field components. Some remarks concerning the connection betw...

Title Nonequilibrium phase transition with gravitational-like interaction in a cloud of cold atoms

Nonequilibrium phase transition with gravitational-like interaction in a cloud of cold atoms.

We propose to use a cloud of laser-cooled atoms in a quasi-two-dimensional trap to investigate a nonequilibrium collapse phase transition in the presence of a gravitational-like interaction. Using theoretical arguments and numerical simulations, we show that, like in two-dimensional gravity, a transition to a collapsed state occurs below a critical temperature. In addition and as a signature of...

Interacting fermionic atoms in optical lattices diffuse symmetrically upwards and downwards in a gravitational potential.

We consider a cloud of fermionic atoms in an optical lattice described by a Hubbard model with an additional linear potential. While homogeneous interacting systems mainly show damped Bloch oscillations and heating, a finite cloud behaves differently: It expands symmetrically such that gains of potential energy at the top are compensated by losses at the bottom. Interactions stabilize the neces...