paper

Excitation Spectra of Bosons in Optical Lattices from Schwinger-Keldysh Calculation

arXiv:1011.5639 · doi:10.1103/PhysRevA.84.013613

Abstract

Within the Schwinger-Keldysh formalism we derive a Ginzburg-Landau theory for the Bose-Hubbard model which describes the real-time dynamics of the complex order parameter field. Analyzing the excitations in the vicinity of the quantum phase transition it turns out that particle/hole dispersions in the Mott phase map continuously onto corresponding amplitude/phase excitations in the superfluid phase, which have been detected recently by Bragg spectroscopy measurements.

References in corpus (14)

Excitation Spectra of Bosons in Optical Lattices from Schwinger-Keldysh Calculation · wovepaper