報告時間：4月30日 周二 上午10:00
報告題目： Long-range Interaction and its Consequence for Quantum Systems
Long-range interaction plays a crucial role in quantum many-body physics. Particularly long-range interactions between atoms such as dipole-dipole interactions found tremendous interest in recent years. It can give rise to a very curious quantum phenomenon named supersolidity, which refers to a state of matter that accommodates discrete translational symmetry with long-range order whilst maintaining a finite superfluid fraction. Recent experimental breakthroughs have amplified interest in the physics of dipolar quantum gases and the long-standing search for supersolid states in such systems. In the first part of this talk, we show that dipolar Bose-Einstein condensates are promising candidates for realizing states with a significant superfluid fraction beyond what is possible with systems where quantum fluctuation can be neglected.
Besides the natural long-range interaction, we propose a scheme to engineer effective/synthetic atom-atom interaction mediated by photons with the assistance of a mirror in the second part. Comparing with its natural counterpart, the mediated interaction can be manipulated widely and trigger novel phenomena.
In recent years, Rydberg-atom-assisted photon-photon interaction attracts a lot of attention. It opens a new avenue to realize photonic devices (such as photon switcher, quantum gates). In the last part of this talk, we will show a general theory of strong optical nonlinearity induced by the Rydberg medium and its typical features.