Seminar
Tuesday, 20 September, 2011
Group Seminar LMU: Quantum Phases of Dipolar Molecules (Double feature)
Tuesday, 20.09.2011 14:00 p.m. (s.t.) in H107, Fakultät für Physik LMU
Prof. Carlos A. R. Sa de Melo, Georgia Institute of Technology
An ensemble of heteronuclear (dipolar) molecules can exhibit many interesting condensed-matter-like properties at ultra-low temperatures because of the long-range range interaction due to their permanent dipole moments [1]. The case of dipolar bosons or fermions in optical lattices may lead to several exotic low temperature phases, which include checkerboard supersolids, striped supersolids and collapsed for dipolar bosons [2] and superfluid phases that break time reversal symmetry and or posses d-wave order parameters for dipolar fermions [3]. In this talk, I discuss the possible quantum phases of dipolar bosons in continuum systems [4] in the two dimensional regime. Furthermore, I present the finite temperature phase diagram of purely repulsive interactions and show that for large dipolar repulsions a dipolar Wigner crystal appears at low temperatures and melts at intermediate temperatures into a dipolar hexatic fluid, before becoming a normal dipolar fluid at higher temperatures. Other exotic intermediate phases such as supersolid and hexatic superfluid (a melted supersolid) are possible. Lastly, I suggest that the experimental characterization of theses phases may be achieved via Bragg scattering techniques.
[1] M. Iskin and C. A. R. Sa de Melo, Phys. Rev. Lett. 99, 110402 (2007).
[2] I. Danshita and C. A. R. Sa de Melo, Phys. Rev. Lett. 103, 225301 (2009).
[3] Li Han and C. A. R. Sa de Melo, arXiv 1006.2072v1.
[4] K. Mitra, C. J. Williams, and C. A. R. Sa de Melo, arXiv 0903.4655v1.