https://doi.org/10.1140/epjb/e2012-30151-x
Regular Article
Quantum phase transitions and coherent tunneling in a bilayer of ultracold atoms with dipole interactions
1
Department of Physics, Captipal Normal University,
Beijing
100048, P.R.
China
2
Beijing National Laboratory for Condensed Matter Physics,
Institute of Physics, Chinese Academy of Sciences, Beijing
100190, P.R.
China
3
International Center for Quantum Materials, Peking
University, Beijing
100871, P.R.
China
4
Department of Physics, Oklahoma State University,
Stillwater, 74078
Oklahoma,
USA
a
e-mail: andrewjee@sina.com
Received: 20 February 2012
Received in final form: 24 April 2012
Published online: 12 June 2012
We study the quantum phase transitions and coherent tunneling in bilayer ultracold bosonic atoms with dipolar interactions at total filling factor νT = 1/2. We demonstrate that, due to the unique characters of the dipole interactions, the ground state of the system may undergo paired quantum Hall state (PQH), dimer quantum-Hall state (DQH), and super-counter-fluidity phase (SCF) by tuning the dipole strength. The SCF state which breaks the easy-plane U(1) symmetry is of particular interest because it can exhibit interlayer coherent tuneling in the incompressible quantum-Hall (QH) state. We suggest that this coherent tunneling current could be observed directly in future experiments.
Key words: Mesoscopic and Nanoscale Systems
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag, 2012