Transport theory for a dilute Bose-Einstein condensate
Transport theory for a dilute Bose-Einstein condensate
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稀玻色-爱因斯坦凝聚态的输运理论
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
Erich D. Gust
中科院分区：
文献类型：
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作者：
L. Reichl;Erich D. Gust
对于非凝聚（T>Tc）的玻色子稀单原子气体，五个缓慢变化的流体动力学变量控制松弛到平衡。这五个变量对应于粒子之间弹性碰撞过程中守恒的量;粒子数，动量（三个分量）和粒子的动能。在Tc以上，弛豫由三个输运系数决定：剪切粘度、热导率和体积粘度（对于稀气体为零）。在玻色-爱因斯坦凝聚的临界温度Tc以下，玻色气体有六种流体动力学模式，但微观碰撞过程发生在Bogoliubov激发（bogolons）之间，只有四个量是守恒的：bogolon动量和能量。这些附加模是由于规范对称性破缺和凝聚态的存在。低于Tc，松弛平衡是由六个传输系数，剪切粘度，热导率，和四个体积粘度（这似乎是可以忽略不计的稀释BEC）。
For a non-condensed (T>Tc) dilute monatomic gas of bosons, five slowly varying hydrodynamic variables govern the relaxation to equilibrium. These five variables correspond to quantities conserved during elastic collisions between the particles; the particle number, momentum (three components), and kinetic energy of the particles. Above Tc, relaxation is governed by three transport coefficients; shear viscosity, thermal conductivity, and bulk viscosity (which is zero for the dilute gas). Below the critical temperature Tc for Bose-Einstein condensation, the boson gas has six hydrodynamic modes, but the microscopic collision processes occur between Bogoliubov excitations (bogolons) and only four quantities are conserved; bogolon momentum and energy. The additional modes are due to the broken gauge symmetry and the presence of the condensate. Below Tc, relaxation to equilibrium is governed by six transport coefficients; shear viscosity, thermal conductivity, and four bulk viscosities (which appear to be negligible for a dilute BEC).