论文标题
时间逆转对称受保护拓扑阶段的稳定性
Stability of Time-Reversal Symmetry Protected Topological Phases
论文作者
论文摘要
在封闭的系统中，众所周知，时间反转对称性会导致Kramers变性并保护非平凡的拓扑状态，例如量子自旋霍尔绝缘子。在这封信中，我们解决了这些问题，如果环境和与环境的耦合也尊重时间反转对称性，那么这些影响是否稳定。通过使用Langevin噪声项的非热汉密尔顿人并利用非铁质线性响应理论，我们表明，可以通过耗散来分割Kramers退化状态的光谱函数，并且可以通过消散引起反向传播边缘状态之间的反向分析。后者导致在量子自旋效应的情况下没有准确的电导量化。例如，我们使用Kane-Mele模型来证明这一点。我们的研究也可以扩展到受时间反向对称性保护的相互作用拓扑阶段。
In a closed system, it is well known that the time-reversal symmetry can lead to Kramers degeneracy and protect nontrivial topological states such as quantum spin Hall insulator. In this letter we address the issue whether these effects are stable against coupling to environment, provided that both environment and the coupling to environment also respect the time-reversal symmetry. By employing a non-Hermitian Hamiltonian with the Langevin noise term and ultilizing the non-Hermitian linear response theory, we show that the spectral functions for Kramers degenerate states can be split by dissipation, and the backscattering between counter-propagating edge states can be induced by dissipation. The latter leads to the absence of accurate quantization of conductance in the case of quantum spin Hall effect. As an example, we demonstrate this concretely with the Kane-Mele model. Our study could also be extended to interacting topological phases protected by the time-reversal symmetry.
