Parts | Days | Selection | Search | Downloads | Help
Q: Fachverband Quantenoptik und Photonik
Q 7: Quantengase: Bosonen im Gitter I
Q 7.2: Talk
Monday, March 2, 2009, 14:15–14:30, VMP 6 HS-A
Bose-Hubbard phase diagram with arbitrary integer filling — •Niklas Teichmann1, Dennis Hinrichs1, Martin Holthaus1, and Andre Eckardt2 — 1Institut für Physik, Carl von Ossietzky Universität, D-26111 Oldenburg, Germany — 2ICFO-Institut de Ciències Fotòniques, E-08860 Castelldefels (Barcelona), Spain
We study the transition from a Mott insulator to a superfluid in the Bose-Hubbard model for a square (2D) and cubic (3D) lattice at zero temperature, employing the method of the effective potential. Converting Kato’s perturbation series into a numerical algorithm capable of reaching high orders, we obtain accurate critical parameters – also for high integer filling factors, which have remained hard to obtain with other methods. Our technique allows us to monitor both the approach to the mean-field limit by considering spatial dimensionalities d > 3, and to the limit of high filling, which refers to an array of Josephson junctions.