A long-lived Higgs mode in a two-dimensional confined Fermi gas

Abstract

The Higgs mode corresponds to the collective motion of particles due to the vibrations of an invisible field. It plays a fundamental role for our understanding of both low and high energy physics, giving elementary particles their mass and leading to collective modes in condensed matter and nuclear systems. The Higgs mode has been observed in a limited number of table-top systems, where it however is characterised by a short lifetime due to decay into a continuum of modes. A major goal which has remained elusive so far, is therefore to realise a long-lived Higgs mode in a controllable system. Here, we show how an undamped Higgs mode can be observed unambiguously in a Fermi gas in a two-dimensional trap, close to a quantum phase transition between a normal and a superfluid phase. We develop a first-principles theory of the pairing and the associated collective modes, which is quantitatively reliable when the pairing energy is much smaller than the trap level spacing, yet simple enough to allow the derivation of analytical results. The theory includes the trapping potential exactly, which is demonstrated to stabilize the Higgs mode by making its decay channels discrete. Our results show how atoms in micro-traps can unravel properties of a long-lived Higgs mode, including the role of confinement and finite size effects.

8 pages, 5 figures

References in corpus (9)

• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
• Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
• The `Higgs' Amplitude Mode at the Two-Dimensional Superfluid-Mott Insulator Transition
• Quantum Magnets under Pressure: Controlling Elementary Excitations in TlCuCl3
• Quantum Fluctuations in the Superfluid State of the BCS-BEC Crossover
• Observation of a two-dimensional Fermi gas of atoms
• Detecting the Amplitude Mode of Strongly Interacting Lattice Bosons by Bragg Scattering
• The Higgs mode in a two-dimensional superfluid
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Cited by in corpus (9)

• Spin-Imbalanced Quasi-Two-Dimensional Fermi Gases
• Measuring pair correlations in Bose and Fermi gases via atom-resolved microscopy
• Pure Goldstone mode in the quench dynamics of a confined ultracold Fermi gas in the BCS-BEC crossover regime
• Generation and decay of Higgs mode in a strongly interacting Fermi gas
• Exciting the long-lived Higgs mode in superfluid Fermi gases with particle removal
• Dynamic structure factor of two-dimensional Fermi superfluid with Rashba spin-orbit coupling
• Few-to-many-particle crossover of pair excitations in a superfluid
• When does a Fermi puddle become a Fermi sea? Emergence of pairing in two-dimensional trapped mesoscopic Fermi gases
• Linear response of a superfluid Fermi gas inside its pair-breaking continuum