Quantum phase transitions in a dimerized Bose-Hubbard model: A DMRG studyAnasuya Kundu and Swapan K. Pati
Theoretical Sciences Unit and DST Unit on Nanoscience, Jawaharlal Nehru Center for Advanced Scientific Research, Jakkur Campus - Bangalore 560064, India
received 14 October 2008; accepted in final form 26 January 2009; published February 2009
published online 18 February 2009
We investigate the phase diagram of a dimerized Bose-Hubbard model, using a density matrix renormalization group technique. We find a new phase, which is the coexistence of superfluid and bond-wave phases, due to the effect of dimerization. Experimentally dimerization in optical lattice can be realized by using two counterpropagating laser beams of different wavelengths. Apart from the conventional superfluidtoMott-insulator transition, we find a new quantum phase transition: from superfluid-bond-wave to Mott-insulator-bond wave phase. Our study suggests a rich phase diagram which can be easily probed.
37.10.Jk - Atoms in optical lattices.
05.30.Jp - Boson systems.
© EPLA 2009