Bogoliubov Excitations in a Kronig-Penney Potential

Abstract

With use of the Kronig-Penney model, we study the excitation spectrum of a Bose-Einstein condensate in a one-dimensional periodic potential. We solve the Bogoliubov equations analytically and obtain the band structure of the excitation spectrum for arbitrary values of the lattice depth. We find that the excitation spectrum is gapless and linear at low energies, and that it is due to the {\it anomalous tunneling} of low energy excitations, predicted by Kagan {\it et al.}.

arXiv comment9 pages, 8 figures

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• Nonlinear Krönig-Penney model
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Cited by in corpus (12)

• Cold Bosons in Optical Lattices
• Phase Dependence of Phonon Tunneling in Bosonic Superfluid-Insulator-Superfluid Junctions
• Stability of Bose-Einstein condensates in a Kronig-Penney potential
• Sound speed of a Bose-Einstein condensate in an optical lattice
• Mechanism of Anomalous Tunneling in Condensed Bose System
• Absence of Anomalous Tunneling of Bogoliubov Excitations for Arbitrary Potential Barrier under the Critical Condensate Current
• Anomalous enhancement of quasiparticle current near a potential barrier in a Bose-Einstein condensate
• Supercurrent behavior of low-energy Bogoliubov phonon and anomalous tunneling effect in a Bose-Einstein condensate
• Supercurrent induced by tunneling Bogoliubov excitations in a Bose-Einstein condensate
• Exact nonlinear Bloch-state solutions for Bose-Einstein condensates in a periodic array of quantum wells
• Unusual behavior of sound velocity of a Bose gas in an optical superlattice at quasi-one-dimension
• Landau and dynamical instabilities of Bose-Einstein condensates with superfluid flow in a Kronig-Penney potential