On the theory of slowing down gracefully

Pramana

Zhou Gang¹  Jürg Fröhlich1¹ 

[1] Theoretische Physik, ETH Zürich, CH-8093 Zürich, Switzerland$$

关键词: Bose–Einstein condensate;    Cerenkov radiation;    Hamiltonian friction;    quantum field theory.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

We discuss the transport of a tracer particle through the Bose–Einstein condensate of a Bose gas. The particle interacts with the atoms in the Bose gas through two-body interactions. In the limiting regime where the particle is very heavy and the Bose gas is very dense, but very weakly interacting (‘mean-field limit’), the dynamics of this system corresponds to classical Hamiltonian dynamics. We show that, in this limit, the particle is decelerated by emission of gapless modes into the condensate (Cerenkov radiation). For an ideal gas, the particle eventually comes to rest. In an interacting Bose gas, the particle is decelerated until its speed equals the propagation speed of the Goldstone modes of the condensate. This is a model of ‘Hamiltonian friction’. It is also of interest in connection with the phenomenon of ‘decoherence’ in quantum mechanics. This note is based on work we have carried out in collaboration with D Egli, I M Sigal and A Soffer.

【 授权许可】

Unknown