Detection of a bosonic metallic state that breaks the $Z_2$ time-reversal symmetry has been recently reported in ${\mathrm{Ba}}_{1-x}{\mathrm{K}}_x{\mathrm{Fe}}_2{\mathrm{As}}_2$ with a doping level $x\approx 0.8$. This is a metallic state of fermionic quadruplets that breaks time-reversal symmetry. As such, it has no condensed Cooper pairs but has a long-range order between fermionic quartets. In the present paper, we investigate the emergence of this phase in a two-component London model via Monte Carlo simulations as a function of various intercomponent couplings.

中文翻译：

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分量间耦合对两分量伦敦模型中时间反演对称破缺费米子四倍态出现的影响

探测到破坏$Z_2$时间反演对称性最近在${巴}_{1-X}{\mathrm{ķ}}_X{铁}_2{\mathrm{作为}}_2$具有兴奋剂水平$X\approx 0.8$. 这是打破时间反演对称性的费米子四联体的金属态。因此，它没有凝聚的库珀对，但在费米子四重奏之间具有长程有序。在本文中，我们通过蒙特卡罗模拟研究了双分量伦敦模型中这一阶段的出现，作为各种分量间耦合的函数。