{"title":"Creating dynamic leakage-free paths using coarse-graining techniques in the presence of decoherence","authors":"S. L. Wu, W. Ma, Lian-Ao Wu","doi":"10.1103/physreva.110.032212","DOIUrl":null,"url":null,"abstract":"We present a method aimed at protecting unitary dynamics in the presence of decoherence, by integrating leakage elimination operators (LEOs) into the system's evolution to create dynamical leakage-free paths. Deriving the dynamical equation for an open quantum system with general drives can be challenging. Our approach avoids the rotating wave approximation and instead uses the coarse-grained averaging technique to derive a quantum master equation for such systems. The combination of the coarse-graining approach and LEO operators appears suitable to study Markovian control methods. We show that employing LEO pulses in specific subspaces can reduce errors arising from undesired transitions due to decoherence. Notably, satisfactory final fidelity can still be achieved even when the reservoir is at a finite temperature. By looking into the dynamical equation governing the quantum state on the dynamical leakage-free path, we provide analytical insights into the effectiveness of the LEO method in suppressing decoherence effects.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":null,"pages":null},"PeriodicalIF":2.9000,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physical Review A","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1103/physreva.110.032212","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"Physics and Astronomy","Score":null,"Total":0}
引用次数: 0
Abstract
We present a method aimed at protecting unitary dynamics in the presence of decoherence, by integrating leakage elimination operators (LEOs) into the system's evolution to create dynamical leakage-free paths. Deriving the dynamical equation for an open quantum system with general drives can be challenging. Our approach avoids the rotating wave approximation and instead uses the coarse-grained averaging technique to derive a quantum master equation for such systems. The combination of the coarse-graining approach and LEO operators appears suitable to study Markovian control methods. We show that employing LEO pulses in specific subspaces can reduce errors arising from undesired transitions due to decoherence. Notably, satisfactory final fidelity can still be achieved even when the reservoir is at a finite temperature. By looking into the dynamical equation governing the quantum state on the dynamical leakage-free path, we provide analytical insights into the effectiveness of the LEO method in suppressing decoherence effects.
我们提出了一种方法,旨在通过将泄漏消除算子(LEOs)整合到系统的演化过程中来创建动态无泄漏路径,从而在存在退相干的情况下保护单元动力学。推导具有一般驱动力的开放量子系统的动力学方程具有挑战性。我们的方法避免了旋转波近似,而是使用粗粒度平均技术来推导此类系统的量子主方程。粗粒化方法与 LEO 算子的结合似乎适合研究马尔可夫控制方法。我们的研究表明,在特定子空间中使用 LEO 脉冲可以减少由于退相干引起的非预期转换所产生的误差。值得注意的是,即使在储层温度有限的情况下,仍然可以实现令人满意的最终保真度。通过研究动态无泄漏路径上量子态的动力学方程,我们对 LEO 方法在抑制退相干效应方面的有效性有了分析性的认识。
期刊介绍:
Physical Review A (PRA) publishes important developments in the rapidly evolving areas of atomic, molecular, and optical (AMO) physics, quantum information, and related fundamental concepts.
PRA covers atomic, molecular, and optical physics, foundations of quantum mechanics, and quantum information, including:
-Fundamental concepts
-Quantum information
-Atomic and molecular structure and dynamics; high-precision measurement
-Atomic and molecular collisions and interactions
-Atomic and molecular processes in external fields, including interactions with strong fields and short pulses
-Matter waves and collective properties of cold atoms and molecules
-Quantum optics, physics of lasers, nonlinear optics, and classical optics