Optical Control of Interactions in Non-equilibrium Fermi Gases
Abstract
We have developed broadly applicable methods for the optical control of two-body scattering interactions in an ultra-cold atomic gas, which is magnetically tuned near a collisional (Feshbach) resonance. Using two-optical fields, we exploit electromagnetically-induced transparency (EIT) to optimize the tradeoff between the tunability of the two body scattering parameters and unwanted optical scattering. By exploiting the high spatial and temporal resolution of optical fields, these techniques enable broad new studies of non-equilibrium dynamics. Our experiments employ an optically-trapped mixture of the two lowest hyperfine states in a 6Li Fermi gas, using two optical fields to create a dark state in the closed molecular channel of a Feshbach resonance. We tested a new theoretical approach for the optical control model, which employs a continuum-dressed (Fano) basis. This model is valid for both the broad (832.2 G) and narrow (543.2 G) resonances in 6Li, which we verified by precise measurements of the momentum dependence of the loss spectra. We constructed a new apparatus, where the optical control beams propagate co-linearly with the axis of a 1064 nm optical dipole trap. The new system enables spatially uniform control of two-body interactions as well as velocity selective control. This method paves the way for new experiments, including optical control of the second virial coefficient and the equation of state, optical control of the effective range for simulation of neutron matter, velocity-selective control of two-body interactions and synthetic FFLO states, and optical control of long range spin-spin interactions to study information scrambling.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 19, 2022
- Accession Number
- AD1184975
Entities
People
- John E. Thomas
Organizations
- North Carolina State University