Compressibility of an ultracold Fermi gas with repulsive interactions

Ye-Ryoung Lee,1 Myoung-Sun Heo,1 Jae-Hoon Choi,1 Tout T. Wang,1,2 Caleb A. Christensen,1 Timur M. Rvachov,1 and Wolfgang Ketterle1 1MIT-Harvard Center for Ultracold Atoms, Research Laboratory of Electronics, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA 2MIT-Harvard Center for Ultracold Atoms, Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA (Received 18 April 2012; published 21 June 2012)