Coherent control of tunneling and quantum phase transitions in strongly driven lattices

The tunneling properties of a quantum system of matter waves inside a periodic potential can be dramatically changed if the potential is driven back and forth. Similarly to an atom in a strong radiation field, the matter waves inside the strongly driven potential are "dressed" and acquire new properties. In this paper, the authors have demonstrated that such dressed matter waves can be coherently and adiabatically loaded and controlled in one, two and three dimensional strongly driven optical lattices. In the driven lattices the tunneling probability and the tunneling phase between adjacent lattice sites become a function of the driving parameters. The regimes in which the driving parameters can be changed without exciting the system have been identified, thus allowing coherent and adiabatic following. This coherent control is then used in order to reversibly induce the superfluid-Mott insulator phase transition by changing the the driving strength.