论文标题
超级操作机构结构和无针对耗散量子过渡的定理
Super-operator structures and no-go theorems for dissipative quantum phase transitions
论文作者
论文摘要
在热力学限制中，由于相干和驱动性动力学之间的竞争，开放量子多体系统的稳态可以进行无等级的相变。在这里，我们考虑了产生时间演变的Liouville超级操作员的马尔可夫系统和阐明结构。在许多感兴趣的情况下，操作员的基础转换可以使liouvillian成为三角形形式，从而可以评估其频谱。光谱间隙设定了渐近衰变速率。超级操作机构结构可用于从下方绑定间隙，表明在大量系统中，耗散相变确实是不可能的，并且稳态的收敛遵循指数的时间衰减。此外，当对角线上的块是遗传学时，Liouvillian Spectra ofey ofey weyl有序关系。例如，该结果适用于Davies发电机和二次系统，并且也适用于各种自旋模型。
In the thermodynamic limit, the steady states of open quantum many-body systems can undergo nonequilibrium phase transitions due to a competition between coherent and driven-dissipative dynamics. Here, we consider Markovian systems and elucidate structures of the Liouville super-operator that generates the time evolution. In many cases of interest, an operator-basis transformation can bring the Liouvillian into a block-triangular form, making it possible to assess its spectrum. The spectral gap sets the asymptotic decay rate. The super-operator structure can be used to bound gaps from below, showing that, in a large class of systems, dissipative phase transitions are actually impossible and that the convergence to steady states follows an exponential temporal decay. Furthermore, when the blocks on the diagonal are Hermitian, the Liouvillian spectra obey Weyl ordering relations. The results apply, for example, to Davies generators and quadratic systems, and are also demonstrated for various spin models.
