Particle creation in Bose--Einstein condensates: Theoretical formulation based on conserving gapless mean field theory
Particle creation in Bose--Einstein condensates: Theoretical formulation based on conserving gapless mean field theory
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DOI：
10.1103/physreva.82.053602
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发表时间：
2010-07
影响因子：
2.9
通讯作者：
Yasunari Kurita;Michikazu Kobayashi;H. Ishihara;M. Tsubota
中科院分区：
文献类型：
--
作者：
Yasunari Kurita;Michikazu Kobayashi;H. Ishihara;M. Tsubota
我们制定的玻色-爱因斯坦凝聚体中的弱相互作用玻色气体的守恒无隙平均场理论的粒子产生现象。通过对平均场理论中的Bogoliubov-de Gennes（BdG）哈密顿量进行再对角化，计算了粒子产生谱。守恒意味着准粒子的产生伴随着对凝聚体的量子反反应。在弯曲时空中，平均场理论中的粒子产生与量子场论中的粒子产生是等价的。得到了受量子反作用影响的有效度规的表达式。在弯曲时空中用QFT得到的粒子产生谱的公式与用BdG哈密顿量再对角化得到的公式是相同的。
We formulate particle-creation phenomena in Bose-Einstein condensates in terms of conserving gapless mean-field theory for weakly interacting Bose gases. The particle-creation spectrum is calculated by rediagonalizing the Bogoliubov-de Gennes (BdG) Hamiltonian in mean-field theory. The conservation implies that quasiparticle creation is accompanied by quantum back reaction to the condensates. Particle creation in this mean-field theory is found to be equivalent to that in quantum field theory (QFT) in curved space-time. An expression is obtained for an effective metric affected by quantum back reaction. The formula for the particle-creation spectrum obtained in terms of QFT in curved space-time is shown to be the same as that given by rediagonalizing the BdG Hamiltonian.