Tindall J, Buča B, Coulthard J R, Jaksch D
Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom.
Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543.
Phys Rev Lett. 2019 Jul 19;123(3):030603. doi: 10.1103/PhysRevLett.123.030603.
We show how, upon heating the spin degrees of freedom of the Hubbard model to infinite temperature, the symmetries of the system allow the creation of steady states with long-range correlations between η pairs. We induce this heating with either dissipation or periodic driving and evolve the system towards a nonequilibrium steady state, a process which melts all spin order in the system. The steady state is identical in both cases and displays distance-invariant off-diagonal η correlations. These correlations were first recognized in the superconducting eigenstates described in Yang's seminal Letter [Phys. Rev. Lett. 63, 2144 (1989)PRLTAO0031-900710.1103/PhysRevLett.63.2144], which are a subset of our steady states. We show that our results are a consequence of symmetry properties and entirely independent of the microscopic details of the model and the heating mechanism.
我们展示了，在将哈伯德模型的自旋自由度加热到无限温度时，系统的对称性如何允许创建具有η对之间长程关联的稳态。我们通过耗散或周期性驱动来引发这种加热，并使系统朝着非平衡稳态演化，这一过程会熔化系统中的所有自旋序。在这两种情况下，稳态都是相同的，并且显示出与距离无关的非对角η关联。这些关联最初是在杨振宁开创性的论文[《物理评论快报》63, 2144 (1989年)PRLTAO0031 - 900710.1103/PhysRevLett.63.2144]中描述的超导本征态中被认识到的，而这些超导本征态是我们稳态的一个子集。我们表明，我们的结果是对称性性质的结果，并且完全独立于模型的微观细节和加热机制。
