Theoretische Physik, ETH Zurich, CH-8093 Zurich, Switzerland.
Phys Rev Lett. 2010 Jun 4;104(22):220402. doi: 10.1103/PhysRevLett.104.220402. Epub 2010 Jun 1.
We study the double occupancy in a fermionic Mott insulator at half filling generated via a dynamical periodic modulation of the hopping amplitude. Tuning the modulation amplitude, we describe a crossover in the nature of doublon-holon excitations from a Fermi golden rule regime to damped Rabi oscillations. The decay time of excited states diverges at a critical modulation strength, signaling the transition to a dynamically bound nonequilibrium state of doublon-holon pairs. A setup using a fermionic quantum gas should allow the study of the critical exponents.
我们研究了通过 hopping 幅度的动态周期性调制在半充满的费米莫特绝缘体中产生的双占据。通过调节调制幅度，我们描述了双电子-空穴激发从费米黄金规则区域到阻尼拉比振荡的性质转变。在临界调制强度下，激发态的衰减时间发散，这标志着向双电子-空穴对的动态束缚非平衡态的转变。使用费米量子气体的设置应该允许研究临界指数。
