Excitation spectra and rf-response near the polaron-to-molecule transition from the functional renormalization group
arXiv:1104.1379 · doi:10.1103/PhysRevA.83.063620
Abstract
A light impurity in a Fermi sea undergoes a transition from a polaron to a molecule for increasing interaction. We develop a new method to compute the spectral functions of the polaron and molecule in a unified framework based on the functional renormalization group with full self-energy feedback. We discuss the energy spectra and decay widths of the attractive and repulsive polaron branches as well as the molecular bound state and confirm the scaling of the excited state decay rate near the transition. The quasi-particle weight of the polaron shifts from the attractive to the repulsive branch across the transition, while the molecular bound state has a very small residue characteristic for a composite particle. We propose an experimental procedure to measure the repulsive branch in a Li6 Fermi gas using rf-spectroscopy and calculate the corresponding spectra.
15 pages, 13 figures; v2: version published in Phys. Rev. A
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Cited by in corpus (11)
- Attractive and repulsive Fermi polarons in two dimensions
- Self-energy flows in the two-dimensional repulsive Hubbard model
- Ultracold atoms and the Functional Renormalization Group
- Polaronic atom-trimer continuity in three-component Fermi gases
- Quantum critical transport in the unitary Fermi gas
- Bloch oscillations of bosonic lattice polarons
- Shear viscosity and spin diffusion in a two-dimensional Fermi gas
- Diagrammatic Monte Carlo study of mass-imbalanced Fermi-polaron system
- The p-wave polaron
- Imaginary polarization as a way to surmount the sign problem in ab initio calculations of spin-imbalanced Fermi gases
- Pairing and radio-frequency spectroscopy in two-dimensional Fermi gases