Physik Department, Technische Universität München, 85747 Garching, Germany.
Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Phys Rev Lett. 2014 Apr 11;112(14):143003. doi: 10.1103/PhysRevLett.112.143003. Epub 2014 Apr 8.
The quantum dynamics of the electromagnetic light mode of an optical cavity filled with a coherently driven Fermi gas of ultracold atoms strongly depends on the geometry of the Fermi surface. Superradiant light generation and self-organization of the atoms can be achieved at low pumping threshold due to resonant atom-photon umklapp processes, where the fermions are scattered from one side of the Fermi surface to the other by exchanging photon momenta. The cavity spectrum exhibits sidebands that, despite strong atom-light coupling and cavity decay, retain narrow linewidth, due to absorptionless transparency windows outside the atomic particle-hole continuum and the suppression of broadening and thermal fluctuations in the collisionless Fermi gas.
充满相干驱动的超冷原子费米气体的光腔的电磁光模式的量子动力学强烈依赖于费米面的几何形状。由于共振原子-光子 umklapp 过程，在低泵浦阈值下可以实现超辐射光产生和原子的自组织，其中费米子通过交换光子动量从费米面的一侧散射到另一侧。腔谱表现出边带，尽管存在强原子-光耦合和腔衰减，但由于在原子粒子-空穴连续体外存在无吸收透明窗口以及在无碰撞费米气体中抑制了展宽和热涨落，边带仍保持窄线宽。
