Gibbons-Hawking effect in the sonic de Sitter space-time of an expanding Bose-Einstein-condensed gas.
- P. Fedichev, U. R. Fischer
- PhysicsPhysical Review Letters
- 15 April 2003
It is shown that a two-level system created at the center of the trap, an atomic quantum dot interacting with phonons, observes a thermal Bose distribution at the de Sitter temperature.
Vortex states of rapidly rotating dilute Bose-Einstein condensates.
- U. R. Fischer, G. Baym
- PhysicsPhysical Review Letters
- 23 November 2001
We show that, in the Thomas-Fermi regime, the cores of vortices in rotating dilute Bose-Einstein condensates adjust in radius as the rotation velocity, Omega, grows, thus precluding a phase…
Quantum simulation of cosmic inflation in two-component Bose-Einstein condensates
- U. R. Fischer, R. Schutzhold
- Physics
- 21 June 2004
Generalizing the one-component case, we demonstrate that the propagation of sound waves in two-component Bose-Einstein condensates can also be described in terms of effective sonic geometries under…
Motion of quantized vortices as elementary objects
- U. R. Fischer
- Physics
- 29 July 1999
Abstract The general local, nondissipative equations of motion for a quantized vortex moving in an uncharged laboratory superfluid are derived from a relativistic, co-ordinate invariant framework…
Riemannian geometry of irrotational vortex acoustics.
- U. R. Fischer, M. Visser
- PhysicsPhysical Review Letters
- 10 October 2001
The scattering angle for phonon rays is shown to be quadratic in the small quantity Gamma/2pi(cb), where Gamma is the vortex circulation, c the speed of sound, and b the impact parameter.
Stability of quasi-two-dimensional Bose-Einstein condensates with dominant dipole-dipole interactions
- U. R. Fischer
- Physics
- 15 June 2005
We consider quasi-two-dimensional atomic or molecular Bose-Einstein condensates with both contact and dipole-dipole interactions. It is shown that as a consequence of the dimensional reduction, and…
Quantum backreaction in dilute Bose-Einstein condensates
- R. Schutzhold, M. Uhlmann, Yan Xu, U. R. Fischer
- Physics
- 23 March 2005
For many physical systems which can be approximated by a classical background field plus small (linearized) quantum fluctuations, a fundamental question concerns the correct description of the…
On the space-time curvature experienced by quasiparticle excitations in the Painlevé-Gullstrand effective geometry
- U. R. Fischer, M. Visser
- Physics
- 8 May 2002
Existence of long-range order for trapped interacting bosons.
- U. R. Fischer
- PhysicsPhysical Review Letters
- 20 April 2002
We derive an inequality governing "long-range" order for a localized Bose-condensed state, relating the condensate fraction at a given temperature with effective curvature radius of the condensate…
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