微波调制的里德堡原子集体量子跳跃

对于一个三能级原子体系,原子的两个基态能级通过微波耦合起来,其中一个基态能级可被激发到里德堡态,从而可观察量子跳跃现象.本文采用量子轨线方法研究了微波调制的里德堡原子集体量子跳跃.研究结果表明,微波耦合基态能级可以提高光子关联,增强光子聚束效应,即使较少的原子中也可以观察到系统在高里德堡占据数态和低里德堡占据数态之间的切换.这一结果为将来进一步研究里德堡自旋晶格中的多体动力学提供了新思路.     

Superradiance-Driven Phonon Laser

We propose to enhance the generation of a phonon laser by exploiting optical superradiance. In our scheme, the optomechanical cavity contains a movable membrane, which supports a mechanical mode, and the superradiance cavity can generate the coherent collective light emissions by applying a transverse pump to an ultracold intracavity atomic gas. The superradiant emission turns out to be capable of enhancing the phonon laser performance.This indicates a new way to operate a phonon laser with the assistance of coherent atomic gases trapped in a cavity or lattice potentials.     

Quantum superchemistry of de Broglie waves: New wonderland at ultracold temperature

The experimental realization of atomic Bose-Einstein condensation at ultracold temperature has led to rapid advances in creating and manipulating cold molecules, and which has given birth to a new research field of quantum matter-wave superchemistry. Contrary to the classical Arrhenius law, the tunneling-dominated ultracold reactions can be realized through the highly-controlled magneto-optical technique. Novel quantum effects have been identified in these cold reactions, such as the super-selectivity rule in dissociating triatomic molecules, and the quantum size (vessel-shape) effect. In this review, we focus on a variety of new achievements in this fascinating matter-wave wonderland, including the quantum finite-number effect and double-slit interference in assembling cold molecules, the quantum noise in triggering collective abstraction reaction, and the magnetic phase transition in a laser-catalyzed quantum spin-mixing gas. The practical applications of matter-wave superchemistry are also introduced, such as the optical information storage via quantum photo-association, and the laser-enhanced creation of spinor or even chiral molecules.