超强耦合下受限量子系统的量子相干效应及其量子调控

Recently, in some artificial confined quantum systems, the light-atom coupling strength has been enhanced to be comparable to the atom or the light field frequency. This parameter regime is known as the ultrastrong coupling regime. In this regime, the counter-rotating interactions will induce some measurable physical effects, which leads to the breakdown of the rotating-wave approximation (RWA). To develop a new theory beyond the RWA to describe the ultrastrongly coupled and confined quantum systems becomes a basic research topic, which has extensive application in quantum information process, quantum coherent devices and quantum control. In this project, we will study the following topics. First, we will explore some optimized scheme for controlling various ultrastrong interactions between atoms and confined photons. Second, we will study new quantum coherent effects and uncover their physical mechanisms in quantum systems composed of atoms isotropic and anisotropic ultrastrongly coupled to confined photons. It will be related to virtual photon effects, the conversion between real and virtual photons. Third, we will explore and exploit the potential applications of these quantum coherent effects to other fields such as quantum information science and quantum coherent device physics. We will try our best to promote the development of the theory beyond the RWA by taking the methods in quantum optics, comparing the analytical solutions and numerical simulations, and research progresses at home and abroad. The research results will be beneficial in the fields of quantum optics, semiconductor systems, and circuit quantum electrodynamics.

近年来，在一些人工受限量子系统，光与原子耦合的强度可增加至与原子或光场频率相比拟的数量级,这被称作超强耦合。在超强耦合区，非旋转波相互作用将引发可观的物理效应，从而旋转波近似失效。发展超越旋转波近似的理论来描述超强耦合受限系统成为基础研究的一个热点，并将在量子信息处理、量子相干器件、量子调控等方面有广泛的应用前景。本项目拟将研究如下内容：第一,探讨原子超强耦合受限光子的各种相互作用的优化调控方案。第二, 研究原子各向同性、各向异性超强耦合受限光子的量子相干效应并揭示其物理机制，如虚光子效应、虚实光子转换等。第三，探求并推动这些新型量子相干效应在量子信息科学和量子相干器件物理等领域的应用。我们用量子光学中的方法，解析和数值模拟相结合，联系国内外研究进展，力争促进超越旋转波近似的理论发展。本项研究将在量子光学，半导体固态系统, 线路量子电动力学等领域有重要的意义。

在本项目执行期间，我们总体上按照原定计划开展研究，同时也根据本研究领域的前沿发展动态适当地对研究内容进行了微小的调整。我们主要采用量子光学领域中传统的解析推导与数值计算相结合的方法，研究了非旋转波相互作用的量子调控、量子演化速度调控、耦合腔系统中光子的量子统计性质、弱力探测、耦合力学振子的量子冷却、超强腔光力耦合的量子模拟、宏观量子叠加态的制备等物理问题，获得了一系列创新性成果。本项目的研究对超强耦合条件下的新奇量子效应的发现、量子态的操控、量子相干器件的设计具有重要理论意义，对量子信息处理的物理过程的理解以及量子信息处理技术和高精密测量技术的发展具有积极的推动作用。