It is shown, through a mean-field description, that the ground state of weakly interacting Bose particles in a quasi-one-dimensional box trap can be converted into an excited stationary state by an almost adiabatic cyclic operation that involves a quench: A sharp impurity potential is applied, and its strength is varied during the cycle, which induces a nonequilibrium stationary state exhibiting the inversion of population. This process is robust in the sense that the resultant stationary state is almost independent of the details of the cycle, such as the position of the impurity, as long as the cycle is far enough from critical regions. The case of the failure of the population inversion due to the strong interparticle interactions is also examined.

中文翻译：

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通过几乎绝热的循环从基态冷凝物产生非平衡稳态

通过平均场描述显示，准一维盒形陷阱中弱相互作用的玻色粒子的基态可以通过涉及淬灭的几乎绝热循环操作转换为激发的稳态。施加了杂质电势，并且其强度在循环过程中发生了变化，这导致了显示出种群反转的非平衡稳态。从最终的稳态几乎与循环的细节（例如杂质的位置）无关的意义上讲，此过程是可靠的，只要循环离临界区域足够远即可。还检查了由于强烈的粒子间相互作用而导致种群反转失败的情况。