The post-graphene era: strongly interacting Dirac fermions with cold atoms

KTH/Nordita/SU seminar in Theoretical Physics [before December 2013]

Wednesday 26 August 2009
from 11:00
to 12:00 at
FB52

Speaker :

Cristiane Morais Smith (University of Utrecht)

Abstract :

Uniform magnetic fields are ubiquitous in nature, but this is not the case for staggered magnetic fields. I will discuss an experimental set-up recently proposed by us [1], which may allow for the realization of a "staggered magnetic field" in a 2D optical lattice loaded with cold atoms. If the lattice is loaded with
bosons, the effective Hamiltonian of the system is a Bose-Hubbard one,
with complex and anisotropic hopping coefficients. A very rich phase
diagram emerges from the model: besides the usual Mott-insulator and
zero-momentum condensate, a new phase with a finite momentum condensate
becomes the ground-state at high-rotation [2]. An extension for
fermionic atoms leads to an anisotropic Dirac spectrum, which is relevant
to graphene and high-Tc superconductors [2]. When the system is loaded
with a mixture of fermions and bosons, an unconventional superconducting phase may be realized [3].
[1] A. Hemmerich and C. Morais Smith, Phys. Rev. Lett. 99,
113002
(2007).
[2] Lih-King Lim, A. Hemmerich, and C. Morais Smith, Phys.
Rev. Lett.
100, 130402 (2008).
[3] Lih-King Lim, A. Lazarides, A. Hemmerich, and C. Morais
Smith,
arXiv:0905.1281 (2009).