Cooling a strongly-interacting quantum gas by interaction modulation

We present a cooling method for a strongly-interacting trapped quantum gas. By applying a magnetic field modulation with frequencies close to the binding energy of a molecular bound state we selectively remove dimers with high kinetic energy from the sample. We demonstrate cooling of the sample over a wide range of interaction strengths and measure a high cooling efficiency of $\gamma =4$ that exceeds all previous cooling near Feshbach resonances.