@article{arunkumar_jagannathan_thomas_2019, title={Designer Spatial Control of Interactions in Ultracold Gases}, volume={122}, ISSN={["1079-7114"]}, DOI={10.1103/PhysRevLett.122.040405}, abstractNote={Designer optical control of interactions in ultracold atomic gases has wide applications, from creating new quantum phases to modeling the physics of black holes. We demonstrate wide tunability and spatial control of interactions in a two-component cloud of ^{6}Li fermions, using electromagnetically induced transparency. With two control fields detuned ≃1.5  THz from atomic resonance, megahertz changes in the frequency of one optical beam tune the measured scattering length over the full range achieved by magnetic control, with negligible (10^{-6}) effect on the net optical confining potential. A 1D "sandwich" of resonantly and weakly interacting regions is imprinted on the trapped cloud and broadly manipulated with sub-MHz frequency changes. All of the data are in excellent agreement with our continuum-dressed state theoretical model of optical control, which includes both the spatial and momentum dependence of the scattering amplitude.}, number={4}, journal={PHYSICAL REVIEW LETTERS}, author={Arunkumar, N. and Jagannathan, A. and Thomas, J. E.}, year={2019}, month={Feb} }
 @article{jagannathan_arunkumar_joseph_thomas_2016, title={Optical Control of Magnetic Feshbach Resonances by Closed-Channel Electromagnetically Induced Transparency}, volume={116}, ISSN={["1079-7114"]}, DOI={10.1103/physrevlett.116.075301}, abstractNote={We control magnetic Feshbach resonances in an optically trapped mixture of the two lowest hyperfine states of a ^{6}Li Fermi gas, using two optical fields to create a dark state in the closed molecular channel. In the experiments, the narrow Feshbach resonance is tuned by up to 3 G. For the broad resonance, the spontaneous lifetime is increased to 0.4 s at the dark-state resonance, compared to 0.5 ms for single-field tuning. We present a new model of light-induced loss spectra, employing continuum-dressed basis states, which agrees in shape and magnitude with loss measurements for both broad and narrow resonances. Using this model, we predict the trade-off between tunability and loss for the broad resonance in ^{6}Li, showing that our two-field method substantially reduces the two-body loss rate compared to single-field methods for the same tuning range.}, number={7}, journal={PHYSICAL REVIEW LETTERS}, author={Jagannathan, A. and Arunkumar, N. and Joseph, J. A. and Thomas, J. E.}, year={2016}, month={Feb} }