Spectrum and Dynamics of the BCS-BEC Crossover from a Few-Body Perspective

2007/01/31 by Javier von Stecher, Chris H. Greene · 3 citations
Physics and Astronomy · #Atomic and Subatomic Physics Research #Coherence (philosophical gambling strategy) #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Crossover #Fermi Gamma-ray Space Telescope #Fermi's golden rule #Fermion #Pairing #Physics #Quantum mechanics #Quantum, superfluid, helium dynamics #Scattering #Scattering length #Statistical physics #Superconductivity #cond-mat.supr-con #nucl-th #physics.atom-ph #quant-ph

paper · pdf · doi:10.1103/physrevlett.99.090402

4 pages, final version to appear in PRL

arxiv created 2007/08/23 · openalex publication_date 2007/08/31 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

The spectrum of two spin-up and two spin-down fermions in a trap is calculated using a correlated Gaussian basis throughout the range of the BCS-BEC crossover. These accurate calculations provide a few-body solution to the crossover problem. This solution is used to study the time evolution of the system as the scattering length is changed, mimicking experiments with Fermi gases near Fano-Feshbach resonances. The structure of avoiding crossings in the spectrum allow us to understand the dynamics of the system as a sequence of Landau-Zener transitions. Finally, we propose a ramping scheme to study atom-molecule coherence.

Citations

• Dynamic Projection on Feshbach Molecules: A Probe of Pairing and Phase Fluctuations
• Nonlinear Adiabatic Passage from Fermion Atoms to Boson Molecules
• Emergence of a molecular Bose–Einstein condensate from a Fermi gas
• Stable85RbBose-Einstein Condensates with Widely Tunable Interactions
• A two-atom picture of coherent atom–molecule quantum beats
• Inserting Two Atoms into a Single Optical Micropotential
• Nonequilibrium Dynamics and Thermodynamics of a Degenerate Fermi Gas Across a Feshbach Resonance
• Weakly Bound Dimers of Fermionic Atoms
• Bose-Einstein Condensation of Molecules
• Observation of Bose-Einstein Condensation of Molecules

Cited by

• Energy spectrum of harmonically trapped two-component Fermi gases: Three- and four-particle problem
• Universal Properties of a Trapped Two-Component Fermi Gas at Unitarity
• Few-body ultracold reactions in a Bose-Fermi mixture