Beliaev damping provides a fundamental mechanism for dissipation of quasiparticles. Previous research has shown that the two-component internal degrees of freedom has no nontrivial effect on Beliaev damping. Here we provide the first example where the spinor nature of Bose gases can manifest itself in the Beliaev damping by way of spin-obit coupling. We identify novel features of Beliaev decay rate due to spin-orbit coupling, in particular, it shows explicit dependence on the spin-density interaction and diverges at the interaction-modified phase boundary between the zero-momentum and plane-wave phases. This represents a manifestation of the effect of spin-orbit coupling in the beyond-mean-field regime, which by breaking Galilean invariance couples excitations in the density- and spin-channels. We further show that the measurement of Beliaev damping rate is experimentally feasible through the measurement of spin polarizability susceptibility which has been already achieved in spin-orbit-coupled Bose gases.

中文翻译：

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自旋轨道耦合玻色-爱因斯坦凝聚物的Beliaev阻尼

Beliaev阻尼为准粒子的耗散提供了基本机制。先前的研究表明，两部分内部自由度对Beliaev阻尼没有不平凡的影响。在这里，我们提供第一个示例，其中玻色气体的自旋性质可以通过自旋-位耦合在Beliaev阻尼中体现出来。我们确定了由于自旋轨道耦合而产生的Beliaev衰减率的新特征，特别是它显示了对自旋密度相互作用的明确依赖性，并且在零动量相位与平面波相位之间的相互作用修饰相界处发生了发散。这代表了自平均轨道范围内自旋轨道耦合效应的体现，该效应通过打破伽利略不变性而在密度和自旋通道中耦合激发。