Gaussian quantum fluctuations in the superfluid-Mott phase transition
arXiv:1808.09338 · doi:10.1103/PhysRevA.99.023614
Abstract
Recent advances in cooling techniques make now possible the experimental study of quantum phase transitions, which are transitions near absolute zero temperature accessed by varying a control parameter. A paradigmatic example is the superfluid-Mott transition of interacting bosons on a periodic lattice. From the relativistic Ginzburg-Landau action of this superfluid-Mott transition we derive the elementary excitations of the bosonic system, which contain in the superfluid phase a gapped Higgs mode and a gappless Goldstone mode. We show that this energy spectrum is in good agreement with the available experimental data and we use it to extract, with the help of dimensional regularization, meaningful analytical formulas for the beyond-mean-field equation of state in two and three spatial dimensions. We find that, while the mean-field equation of state always gives a second-order quantum phase transition, the inclusion of Gaussian quantum fluctuations can induce a first-order quantum phase transition. This prediction is a strong benchmark for next future experiments on quantum phase transitions.
7 pages, 4 figures, to be published in Physical Review A
References in corpus (9)
- Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms
- Amplitude / Higgs Modes in Condensed Matter Physics
- The `Higgs' Amplitude Mode at the Two-Dimensional Superfluid-Mott Insulator Transition
- Mott insulator to superfluid transition in the Bose-Hubbard model: a strong-coupling approach
- Dynamical properties of ultracold bosons in an optical lattice
- Zero-point energy of ultracold atoms
- Transport and Entanglement Generation in the Bose-Hubbard Model
- Spontaneous symmetry breaking and Higgs mode: comparing Gross-Pitaevskii and nonlinear Klein-Gordon equations
- Contour-time approach to the Bose-Hubbard model in the strong coupling regime: Studying two-point spatio-temporal correlations at the Hartree-Fock-Bogoliubov level