We propose a method to probe ground states with distinct properties in binary mixtures trapped in small-ring lattices. The technique exploits the nonequilibrium particle current behavior generated by a nonadiabatic change of the interaction between the species of the binary mixture. The analysis of the current fluctuations in the Fourier space reveals a correspondence between the frequency peaks and specific particle-hole excitations, thereby performing a many-body spectroscopy of the ground state of the system. We show, for a small system, that the read out of the frequency spectrum can be used to detect essential features of a pair superfluid quantum phase. Remarkably, large frequency shifts of the spectral peaks provide an indication of relevant differences between ground states located very near in the parameter space. This spectral behavior allows establishing a criterium to determine in experiments changes in the properties of the ground state in small systems.

中文翻译：

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具有二元混合物的小环格子中用于光谱学的粒子的束流

我们提出了一种方法来探测陷入小环晶格的二元混合物中具有不同性质的基态。该技术利用了二元混合物物质之间相互作用的非绝热变化所产生的非平衡粒子电流行为。对傅立叶空间中电流波动的分析揭示了频率峰值与特定的粒子-空穴激励之间的对应关系，从而对系统的基态进行了多体光谱分析。我们显示，对于一个小型系统，频谱的读数可用于检测一对超流体量子相的基本特征。值得注意的是，频谱峰值的大频移提供了位于参数空间中非常近的基态之间的相关差异的指示。