2011/05/31 by Qi Zhou, J. V. Porto, S. Das Sarma · 18 citations
Chemistry · Physics and Astronomy · #Asymmetry #Atomic physics #Band gap #Brillouin zone #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Diffraction #Electronic band structure #Empty lattice approximation #Excited state #Lattice (music) #Optical lattice #Particle in a one-dimensional lattice #Physics #Point reflection #Quantum mechanics #Reciprocal lattice #Spectroscopy and Laser Applications #Strong Light-Matter Interactions #Superlattice #cond-mat.quant-gas
paper · pdf · doi:10.1103/physreva.84.031607
published in Physical Review A 84(3) (American Physical Society) · 4pages, 3 figures
openalex publication_date 2011/09/26 · arxiv created 2011/09/29 · arxiv updated 2015/05/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We show theoretically that interaction effects in a double-well optical lattice can induce condensates in an excited band. For a symmetric double-well lattice, bosons condense into the bottom of the excited band at the edge of the Brillouin zone if the chemical potential is above a critical value. For an asymmetric lattice, a condensate with zero momentum is automatically induced in the excited band by the condensate in the lowest band. This is due to a combined effect of interaction and lattice potential, which reduces the band gap and breaks the inversion symmetry. Our work can be generalized to a superlattice composed of multiple-well potentials at each lattice site, where condensates can be induced in even higher bands.