Nonexponential one-body loss in a Bose-Einstein condensate

Abstract

We have studied the decay of a Bose-Einstein condensate (BEC) of metastable helium atoms in an optical dipole trap. In the regime where two-and three-body losses can be neglected we show that the Bose-Einstein condensate and the thermal cloud show fundamentally different decay characteristics. The total number of atoms decays exponentially with time constant τ ; however, the thermal cloud decays exponentially with time constant 4 3 τ and the condensate decays much faster, and nonexponentially. We show that this behavior, which should be present for all BECs in thermal equilibrium with a considerable thermal fraction, is due to a transfer of atoms from the condensate to the thermal cloud during its decay.

Asymmetric many-body loss in a bosonic double well

“…Interaction-induced nonexponential tunnelling decay has been found in different contexts of BEC evolutions, see e.g. [22][23][24][25]. This effect probes the role of interactions and can, in principle, be used to engineer the tunnelling decay, see the example reported in reference [23], where the compensation of an energy detuning from an internal resonance by the interaction-induced energy shift is exploited.…”

Ensemble master equation for a trapped-atom clock with one- and two-body losses

“…(14) to N 0 the final ensemble density matrix elements with the unitary part of the ensemble master equation [Eq. (16)] constructed from the two-level Hamiltonian in the rotating wave approximation with one-body and two-body losses and pure dephasing become…”

“…For this reason one-or twobody loss only is typically included [4,[10][11][12][13][14][15]. However, achievable vacuum is imperfect and differs noticeably between systems [16], and the actual pressures during data acquisition range from 10 −11 to 10 −9 Torr, influencing the one-body decay rates. Albeit, two-body losses alone lead to population trapping [ [17, p. 102] and Eqs.…”

Gradient corrections to the local-density approximation in the one-dimensional Bose gas

“…The effects of the latter on the dynamics of the gas can become important at longer times, and they are typically hard to describe theoretially. Cold atom experiments involve various loss processes, for instance one-body losses resulting from scattering with background thermal atoms [2], which can be significant. Inelastic two-body collisions can occur naturally or be intentionally engineered, leading to two-body losses [3][4][5][6][7][8][9][10].…”

“…For each cases, K consecutive atoms are removed and are lost in the 'environment'. In this paper losses are modeled by the Lindblad equation (2).…”