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Q: Fachverband Quantenoptik und Photonik

Q 22: Quantengase: Wechselwirkungseffekte 1

Q 22.3: Vortrag

Dienstag, 13. März 2012, 11:15–11:30, V7.03

Perturbative calculation of critical exponents for the Bose-Hubbard model — •Dennis Hinrichs¹, Axel Pelster², and Martin Holthaus¹ — ¹Institut für Physik, Carl von Ossietzky Universität Oldenburg, 26111 Oldenburg — ²Hanse-Wissenschaftskolleg, 27753 Delmenhorst

The process-chain approach is a powerful tool for carrying out perturbative calculations for many-body lattice systems in high order of the hopping strength [1]. In combination with the method of the effective potential, this technique permits us to determine characteristic quantities with an accuracy far greater than that of mean-field methods.

In this talk I will concentrate on the calculation of the superfluid and of the condensate density for the Bose-Hubbard model, and demonstrate how the process-chain approach can be employed for obtaining the critical exponents characterizing the system near the superfluid-to-Mott insulator quantum phase transition.

[1] N. Teichmann, D. Hinrichs, M. Holthaus, and A. Eckardt, PRB 79, 224515 (2009).