用强电磁场改变不稳定系统的寿命

强电磁场引起的自发发射和寿命修正

Spontaneous emission and lifetime modification caused by an intense electromagnetic field

我们研究了一个三能级系统（如原子或分子）的时间演化，该系统最初处于激发态，并沐浴在一个调谐到另一个能级跃迁频率的激光场中。的自发发射的特点进行了研究和初始状态的寿命进行了评估：费米“黄金法则”仍然适用，但壳层上的矩阵元素依赖于强度的激光场。通常，寿命是激光强度的递减函数。我们讨论的现象可以被看作是一个“逆”量子芝诺效应，并可以分析的修饰状态。

Cavity-assisted squeezing and entanglement: Non-adiabatic effects and optimal cavity-atomic ensemble matching

We investigate theoretically quantum entanglement of light with the collective spin polarization of a cold atomic ensemble in cavity-assisted Raman schemes. Previous works concentrated mostly on the bad cavity limit where the signals are much longer than the cavity field lifetime. In view of atomic relaxation and other imperfections, there may arise a need to speed-up the light-atoms interface operation. By increasing the cavity field lifetime, one can achieve better light-matter coupling and entanglement. In our work, we consider the non-adiabatic effects that become important beyond the bad …

Entanglement of unstable atoms: modifications of the emission properties

We analyse the influence of entanglement on the emission properties of atoms. To this end, first, we propose a scheme for the preparation of a pair of entangled Helium atoms, one in the ortho and the other in the para spin configuration. We discuss a realistic scenario for this process, based in the double ionization of He by intense laser fields. These states are used to analyse disentanglement and the role of entanglement in the spontaneous emission from the pair. In particular, we show that the decaying rate of an entangled atom is different from that in a product state, modifying the tempo…

利用具有磁笼抑制电离效应的长寿命Rydberg-Landau原子进行量子计算

Quantum computation with longlived Rydberg-Landau atoms featuring suppressed ionization by the Magnetic Cage

针对Rydberg原子寿命短和易电离限制量子计算的问题，提出在2.5 Tesla强磁场下构建具有长寿命和抗电离特性的Rydberg-Landau态，以实现高保真量子操作并支持更复杂的量子算法。

Laser Trapping of Circular Rydberg Atoms

Rydberg atoms are remarkable tools for quantum simulation and computation. They are the focus of an intense experimental activity mainly based on low-angular-momentum Rydberg states. Unfortunately, atomic motion and levels lifetime limit the experimental time-scale to about 100$μ$s. Here, we demonstrate laser trapping of long-lived circular Rydberg states for up to 10ms. Our method is very general and opens many opportunities for quantum simulation. The 10ms trapping time corresponds to thousands of interaction cycles in a circular-state-based quantum simulator. It is also promising for quantu…

New schemes for creating large optical Schrodinger cat states using strong laser fields

Recently, using conditioning approaches on the high-harmonic generation process induced by intense laser-atom interactions, we have developed a new method for the generation of optical Schrödinger cat states (M. Lewenstein et al., arXiv:2008.10221 (2020)). These quantum optical states have been proven to be very manageable as, by modifying the conditions under which harmonics are generated, one can interplay between $\textit{kitten}$ and $\textit{genuine cat}$ states. Here, we demonstrate that this method can also be used for the development of new schemes towards the creation of optical Schrö…