Near-unit efficiency of chiral state conversion via hybrid-Liouvillian dynamics
Near-unit efficiency of chiral state conversion via hybrid-Liouvillian dynamics
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DOI：
10.1103/physreva.104.l050405
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发表时间：
2021-05
影响因子：
2.9
通讯作者：
Parveen Kumar;K. Snizhko;Y. Gefen
中科院分区：
文献类型：
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作者：
Parveen Kumar;K. Snizhko;Y. Gefen
在非厄米哈密顿量(NHH)下的演化涉及重大的概率损失。这使得各种NHH效应在量子领域不切实际。相比之下，林布拉德演化守恒概率，便于观察和应用开放量子系统特有的奇异效应。在这里，我们关注手征态转换的影响：围绕一个例外点，多个系统态被转换成单个系统本征模。对于NHH，可能转换为本征模的是纯态，而对于Lindbladians来说，这些通常是混合态。我们考虑混合-Liouvillian进化，它介于Lindbladian和NHH之间，能够结合这两个世界的最好。我们设计的绝热演化协议可以产生手征态的转换，最终态是无几率损失的、高保真的。此外，在连续绝热演化的基础上，我们设计了一个协议，它便于向保真度为1的纯态的转换，同时没有概率损失。利用最近发展起来的实验技术，我们的提议可以在超导量子比特平台上实现。
Following the evolution under a non-Hermitian Hamiltonian (nHH) involves significant probability loss. This makes various nHH effects impractical in the quantum realm. In contrast, Lindbladian evolution conserves probability, facilitating observation and application of exotic effects characteristic of open quantum systems. Here we are concerned with the effect of chiral state conversion: encircling an exceptional point, multiple system states are converted into a single system eigenmode. While for nHH the possible converted-into eigenmodes are pure states, for Lindbladians these are typically mixed states. We consider hybrid-Liouvillian evolution, which interpolates between a Lindbladian and a nHH and enables combining the best of the two worlds. We design adiabatic evolution protocols that give rise to chiral state conversion with $\textit{pure}$ final states, no probability loss, and high fidelity. Furthermore, extending beyond continuous adiabatic evolution, we design a protocol that facilitates conversion to pure states with fidelity 1 and, at the same time, no probability loss. Employing recently developed experimental techniques, our proposal can be implemented with superconducting qubit platforms.