Department of Physics, University of Illinois, 1110 West Green Street, Urbana, Illinois 61801, USA.
Phys Rev Lett. 2013 Aug 9;111(6):063002. doi: 10.1103/PhysRevLett.111.063002. Epub 2013 Aug 8.
Using a 3D spin-dependent optical lattice, we study thermalization and energy exchange between two ultracold Bose gases, one of which is strongly correlated and bound to the lattice and another that is free from the lattice potential. Disruption of interspecies thermalization is revealed through measurements of condensate fraction after the lattice is superimposed on the parabolic confining potential. By selectively heating the lattice-bound species and measuring the rate of heat transfer to the free state, suppression of energy exchange is observed. Comparison with a Fermi's golden rule prediction confirms that this effect is caused by a dispersion mismatch that reduces the phase space available for elastic collisions. This result has critical implications for methods proposed to cool strongly correlated lattice gases.
使用三维自旋依赖的光晶格，我们研究了一个强关联并束缚在晶格上的超冷玻色气体与另一个不受晶格势影响的自由超冷玻色气体之间的热化和能量交换。通过测量晶格叠加在抛物型限制势后凝聚分数，揭示了物种间热化的破坏。通过选择性地加热晶格束缚物种并测量向自由态的传热速率，观察到能量交换的抑制。与费米黄金定则预测的比较证实，这种效应是由色散失配引起的，这减少了弹性碰撞可用的相空间。这个结果对为冷却强关联晶格气体而提出的方法具有关键意义。
