2011/02/03 by Rajdeep Sensarma, K. Sengupta, S. Das Sarma · 11 citations
Physics and Astronomy · #Boson #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Gapless playback #Lattice (music) #Optical lattice #Phase transition #Physics #Quantum mechanics #Quantum phase transition #Quantum, superfluid, helium dynamics #Quasiparticle #Spectroscopy #Strong Light-Matter Interactions #Superconductivity #Superfluidity #cond-mat.quant-gas #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.84.081101
published in Physical Review B 84(8) (American Physical Society) · 5 pages, 2 figures
arxiv created 2011/02/03 · openalex publication_date 2011/08/15 · arxiv updated 2015/03/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We propose an experimental method of optical lattice modulation spectroscopy for studying the spectral function of ultracold bosons in an optical lattice. We show that different features of the single-particle spectral function in different quantum phases can be obtained by measuring the change in momentum distribution after the modulation. In the Mott phase, this gives information about the momentum-dependent gap to particle-hole excitations as well as their spectral weight. In the superfluid phase, one can obtain the spectrum of the gapless Bogoliubov quasiparticles as well as the gapped amplitude fluctuations. The distinct evolution of the response with modulation frequency in the two phases can be used to identify these phases and the quantum phase transition separating them.