TY - JOUR

T1 - Random on-site interactions versus random potential in ultra cold atoms in optical lattices

AU - Gimperlein, H.

AU - Wessel, S.

AU - Schmiedmayer, J.

AU - Santos, Luis

PY - 2005/12/23

Y1 - 2005/12/23

N2 - We consider the physics of lattice bosons in the presence of either disordered on-site chemical potential or disordered on-site interparticle interactions. By means of analytical results using strong-coupling expansion, and numerical results based on quantum Monte Carlo calculations, we show that important qualitative changes in the zero temperature phase diagram are observed when comparing both cases. Although for both types of disorder superfluid, Mott-insulator and Bose-glass phases may be found, we show that in the case of random interactions the Mott-insulating regions shrink and eventually vanish for any finite disorder strength beyond a sufficiently large filling factor. Furthermore, at low values of the chemical potential both the superfluid and Mott insulator are stable towards the formation of a Bose-glass, leading to a possibly non-trivial tricritical point. We discuss possible experimental realizations of both types of disorder in the context of ultra cold atomic gases in optical lattices.

AB - We consider the physics of lattice bosons in the presence of either disordered on-site chemical potential or disordered on-site interparticle interactions. By means of analytical results using strong-coupling expansion, and numerical results based on quantum Monte Carlo calculations, we show that important qualitative changes in the zero temperature phase diagram are observed when comparing both cases. Although for both types of disorder superfluid, Mott-insulator and Bose-glass phases may be found, we show that in the case of random interactions the Mott-insulating regions shrink and eventually vanish for any finite disorder strength beyond a sufficiently large filling factor. Furthermore, at low values of the chemical potential both the superfluid and Mott insulator are stable towards the formation of a Bose-glass, leading to a possibly non-trivial tricritical point. We discuss possible experimental realizations of both types of disorder in the context of ultra cold atomic gases in optical lattices.

UR - http://www.scopus.com/inward/record.url?scp=30444449393&partnerID=8YFLogxK

U2 - 10.1007/s00340-005-2088-7

DO - 10.1007/s00340-005-2088-7

M3 - Article

AN - SCOPUS:30444449393

VL - 82

SP - 217

EP - 224

JO - Applied Physics B: Lasers and Optics

JF - Applied Physics B: Lasers and Optics

SN - 0946-2171

IS - 2 SPEC. ISS.

ER -