Particle-hole character of the Higgs and Goldstone modes in strongly-interacting lattice bosons
ORAL
Abstract
We study the low-energy excitations of the Bose-Hubbard model in the strongly-interacting superfluid phase using a Gutzwiller approach and extract the single-particle and single-hole excitation amplitudes for each mode. We report emergent mode-dependent particle-hole symmetry on specific arc-shaped lines in the phase diagram connecting the well-known Lorentz-invariant limits of the Bose-Hubbard model. By tracking the in-phase particle-hole symmetric oscillations of the order parameter, we provide an answer to the long-standing question about the fate of the pure amplitude Higgs mode away from the integer-density critical point. Furthermore, we point out that out-ofphase oscillations are responsible for a full suppression of the condensate density oscillations of the gapless Goldstone mode. Possible detection protocols are also discussed.
*N. T. acknowledges funding from NSF-DMR- 1309461; also supported by the EUFET Proactive grant AQuS, Project No. 640800 and by Provincia Autonoma di Trento.
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Presenters
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Nandini Trivedi
- The Ohio State University
- Physics, The Ohio State University
- Physics, Ohio State Univ - Columbus
- Ohio State Univ - Columbus
- Physics Department, Ohio State University
- Department of Physics, The Ohio State University
- Ohio State University
- Department of Physics, Ohio State Univ - Columbus