AI 中文总结
本文在可精确求解的周期驱动非厄米Su-Schrieffer-Heeger链中，发现仅双正交的弗洛凯动力学量子相变区域，确立双正交与自归一动力学量子相变的根本区别，为非厄米系统新型非平衡量子现象开辟路径。
AI 中文摘要
非厄米动力学量子相变（DQPTs）在非幺正时间演化下对内积的选择具有固有敏感性。尽管基于关联态的双正交公式提供了具有概率解释的归一化洛施密特回声，但此前研究发现双正交和自归一DQPTs发生在相同参数区域，表明这两种动力学临界性是相伴出现的。本文证明情况并非如此：在一个可精确求解的周期驱动非厄米Su-Schrieffer-Heeger链中，我们发现了一个有限的仅双正交弗洛凯DQPT区域，其中双正交洛施密特率呈现非解析性，而自归一洛施密特率保持平滑。通过解析得到临界条件，显示双正交弗洛凯DQPT的发生与有效弗洛凯哈密顿量的例外线锁定，而自归一临界性无对应的谱边界。此外，对于每个临界动量，双正交DQPT在每个驱动周期内呈现一对临界时间，而自归一DQPT仅呈现一个。我们的结果确立了双正交与自归一DQPT之间的根本区别，从而为非厄米系统中新型非平衡量子现象开辟了一条路径。
英文摘要
Non-Hermitian dynamical quantum phase transitions (DQPTs) are intrinsically sensitive to the choice of inner product under nonunitary time evolution. Although the biorthogonal formulation based on associated states provides a normalized Loschmidt echo with a probabilistic interpretation, previous studies have found biorthogonal and self-normal DQPTs to occur in the same parameter regimes, suggesting that the two forms of dynamical criticality are concomitant. Here we demonstrate that this is not the case. In an exactly solvable periodically driven non-Hermitian Su-Schrieffer-Heeger chain, we uncover a finite biorthogonal-only Floquet DQPT regime, where the biorthogonal Loschmidt rate becomes nonanalytic while the self-normal Loschmidt rate remains smooth. The critical conditions are obtained analytically, showing that the onset of biorthogonal Floquet DQPTs is locked to the exceptional lines of the effective Floquet Hamiltonian, whereas self-normal criticality has no corresponding spectral boundary. Moreover, for each critical momentum, the biorthogonal DQPT exhibits a pair of critical times within every driving period, whereas the self-normal DQPT exhibits only one. Our results establish a fundamental distinction between biorthogonal and self-normal DQPTs, thereby opening a route toward new nonequilibrium quantum phenomena in non-Hermitian systems.
Comments6 pages, 4 figures
