Resonantly enhanced coherence by laser-assisted tunneling
  We study quantum coherence of strongly interacting cold bosons in a double-well potential driven by a laser field. The system is initially in a Fock state and, for either with or without a static tilting field, evolves into the coherent states. The coherence is resonantly enhanced by the photon-assisted tunneling. For the tilted wells, it reveals a two-branch pattern which corresponds to the multiple photon absorption or emission, respectively. 
Hong-Xia Hao, Shiping Feng and Shi-Jie Yang
cond-mat.quant-gas physics.optics