2017/04/19 by Julian Léonard, Andrea Morales, Philip Zupancic +2 · 205 citations
Physics and Astronomy · #Amplitude #Cold Atom Physics and Bose-Einstein Condensates #Continuous symmetry #Goldstone #Goldstone boson #Higgs boson #Higgs field #Phase (matter) #Phase diagram #Physics #Quantum Mechanics and Applications #Quantum mechanics #Quantum, superfluid, helium dynamics #Spontaneous symmetry breaking #Supersolid #Symmetry (geometry) #Symmetry breaking #cond-mat.other #cond-mat.quant-gas #quant-ph
paper · pdf · doi:10.1126/science.aan2608
published in Science 358(6369), 1415-1418 (American Association for the Advancement of Science) · 5+6 pages, 4+4 figures
arxiv created 2017/04/19 · openalex publication_date 2017/12/14 · arxiv updated 2017/12/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Higgs and Goldstone modes are collective excitations of the amplitude and phase of an order parameter that is related to the breaking of a continuous symmetry. We directly studied these modes in a supersolid quantum gas created by coupling a Bose-Einstein condensate to two optical cavities, whose field amplitudes form the real and imaginary parts of a U(1)-symmetric order parameter. Monitoring the cavity fields in real time allowed us to observe the dynamics of the associated Higgs and Goldstone modes and revealed their amplitude and phase nature. We used a spectroscopic method to measure their frequencies, and we gave a tunable mass to the Goldstone mode by exploring the crossover between continuous and discrete symmetry. Our experiments link spectroscopic measurements to the theoretical concept of Higgs and Goldstone modes.