Theoretical Study Of Effective Gauge Potential And Superatoms Based On Rydberg Blockade

The dipole-dipole interaction between Rydberg atoms is very strong due to their large electric dipole moment and prevents more than one Rydberg atom from being excited into the Rydberg state through the resonant light field,which is called the Rydberg blockade effect.In addition,the atoms in the Rydberg state have long spontaneous radiation life.Thus the Rydberg blockade effect has been widely used in quantum information,ultra-cold plasma,atomic coherent excitation and multi-body physics and so on.Based on the strong dipole-dipole interaction between Rydberg atoms,we have studied the following three questions and obtained some innovative research results:First,we have investigated a system consisting of two interacting Rydberg atoms with a ladder-type three-level structure or with a ?-type four-level structure which are driven by the resonant laser fields and obtained the dark states respectively.For the former case the dark states are two-fold degenerate,and five-fold degenerate for the latter.While in a literature [Phys.Rev.Lett.100,170504(2009)],the authors concluded only one dark state for the case of two ladder-type three-level Rydberg atoms.We analyze the reason that induced the misleading there and comment on the method and results in the above reference.Second,based on the dark states for the system of two ?-type four-level structure Rydberg atoms,we propose a method to generate the effective gauge potential by using the theory developed by Wilczek and Zee.Accordingly,we obtain the effective magnetic field which turns out to be generated by magnetic monopoles.Third,we investigate the dynamics of Rydberg superatoms in the quantum optical cavity and propose two schemes to generate tripod quantum entangled states.