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SYHM: Symposium Higgs Modes in Condensed Matter and Quantum Gases

SYHM 1: Higgs Modes in Condensed Matter and Quantum Gases

SYHM 1.2: Invited Talk

Wednesday, March 18, 2015, 15:30–16:00, H 0105

Higgs Particles for Systems with U(1) Symmetry in Two Dimensions — •Lode Pollet — Arnold Sommerfeld Center, Theoretical Physics, LMU Munich, Germany

We present solid evidence for the existence of a Higgs boson in two-dimensional relativistic field theories based on analytically continued results from quantum Monte Carlo simulations of the Bose-Hubbard model in the vicinity of the superfluid-Mott insulator quantum critical point, featuring emergent particle-hole symmetry and Lorentz-invariance. The Higgs boson, seen as a well-defined low-frequency resonance in the spectral density, is quickly pushed to high energies in the superfluid phase and disappears by merging with the broad secondary peak at the characteristic interaction scale. Simulations of a trapped system of ultra-cold Rb-87 atoms demonstrate that the low-frequency resonance feature is lost for typical experimental parameters, while the characteristic frequency for the onset of strong response is preserved. We compute the universal scaling function and comment on the agreements and disagreements with three dimensions and observations of Higgs particles in more traditional solid state experiments.