Berlin 2014 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 32: Poster: Quantum gases, ultracold atoms and molecules

Q 32.32: Poster

Wednesday, March 19, 2014, 16:30–18:30, Spree-Palais

High-Order Strong-Coupling Expansion for Bose-Hubbard Model — Tao Wang^1,2, Xue-Feng Zhang¹, Sebastian Eggert¹, and •Axel Pelster¹ — ¹Physics Department and Research Center OPTIMAS, Technische Universität Kaiserslautern, Germany — ²Department of Physics, Harbin Institute of Technology, China

We apply the process-chain method [1,2] in order to calculate the quantum phase boundary between the Mott insulator and the superfluid phase for bosons in a hypercubic optical lattice within the strong-coupling method [3]. The respective results in 1d, 2d, and 3d, which are obtained up to 12th order and then extrapolated to infinite order, turn out to coincide almost with high-precision Quantum-Monte Carlo results. Finally, we show that these high-order strong-coupling results also follow from a high-order effective potential calculation [2,4,5].

[1] A. Eckardt, Phys. Rev. B 79, 195131 (2009)

[2] N. Teichmann, D. Hinrichs, M. Holthaus, and A. Eckardt, Phys. Rev. B 79, 224515 (2009)

[3] J. K. Freericks and H. Monien, Phys. Rev. B 53, 2691 (1996)

[4] F. E. A. dos Santos and A. Pelster, Phys. Rev. A 79, 013614 (2009)

[5] D. Hinrichs, A. Pelster, and M. Holthaus, Appl. Phys. B 113, 57 (2013)