Massel Francesco, Leskinen Mikko J, Törmä Päivi
Department of Applied Physics, 02015 Helsinki University of Technology, Finland.
Phys Rev Lett. 2009 Aug 7;103(6):066404. doi: 10.1103/PhysRevLett.103.066404.
We consider a strongly repulsive two-component Fermi gas in a one-dimensional optical lattice described in terms of a Hubbard Hamiltonian. We analyze the response of the system to a periodic modulation of the hopping amplitude in the presence of a large two-body interaction. By (essentially) the exact simulations of the time evolution, we find a nontrivial double occupancy frequency dependence. We show how the dependence relates to the spectral features of the system given by the Bethe ansatz. The discrete nature of the spectrum is clearly reflected in the double occupancy after a long enough modulation time. We also discuss the implications of the 1D results to experiments in higher dimensional systems.
我们考虑一个处于一维光学晶格中的强排斥性两分量费米气体,其由哈伯德哈密顿量描述。我们分析了在存在大的两体相互作用时,系统对跳跃幅度的周期性调制的响应。通过(本质上)对时间演化的精确模拟,我们发现了非平凡的双占据频率依赖性。我们展示了这种依赖性与由贝塞耳假设给出的系统光谱特征之间的关系。在足够长的调制时间后,光谱的离散性质清楚地反映在双占据中。我们还讨论了一维结果对高维系统实验的影响。