Institut für Experimentalphysik and Zentrum für Quantenphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
Phys Rev Lett. 2010 May 21;104(20):200403. doi: 10.1103/PhysRevLett.104.200403.
Particles in a perfect lattice potential perform Bloch oscillations when subject to a constant force, leading to localization and preventing conductivity. For a weakly interacting Bose-Einstein condensate of Cs atoms, we observe giant center-of-mass oscillations in position space with a displacement across hundreds of lattice sites when we add a periodic modulation to the force near the Bloch frequency. We study the dependence of these "super" Bloch oscillations on lattice depth, modulation amplitude, and modulation frequency and show that they provide a means to induce linear transport in a dissipation-free lattice.
当处于恒定外力作用下时，完美晶格势中的粒子会产生布洛赫振荡，导致局域化并阻止电导率。对于 Cs 原子的弱相互作用玻色-爱因斯坦凝聚体，当我们在布洛赫频率附近的力上施加周期性调制时，我们观察到在位置空间中具有数百个晶格站点的位移的巨大质心振荡。我们研究了这些“超”布洛赫振荡对晶格深度、调制幅度和调制频率的依赖性，并表明它们提供了一种在无耗散晶格中诱导线性输运的方法。
