Particle-Hole Character of the Higgs and Goldstone Modes in Strongly Interacting Lattice Bosons

Di Liberto, M.; Recati, A.; Trivedi, N.; Carusotto, I. und Menotti, C. (2018): Particle-Hole Character of the Higgs and Goldstone Modes in Strongly Interacting Lattice Bosons. In: Physical Review Letters, Bd. 120, Nr. 7, 73201

Abstract

We study the low-energy excitations of the Bose-Hubbard model in the strongly interacting superfluid phase using a Gutzwiller approach. We extract the single-particle and single-hole excitation amplitudes for each mode and 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-of-phase symmetric oscillations in the gapless Goldstone mode are responsible for a full suppression of the condensate density oscillations. Possible detection protocols are also discussed.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 0031-9007
• Sprache: Englisch