Department of Physics and CeOPP, University of Paderborn, Warburger Str. 100, D-33098, Paderborn, Germany.
Centro de Física Teórica e Computacional and Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Ed. C8, Lisboa, 1749-016, Portugal.
Sci Rep. 2017 Jun 9;7(1):3194. doi: 10.1038/s41598-017-03400-w.
We demonstrate that nonlinearity may play a constructive role in supporting Bloch oscillations in a model which is discrete, in one dimension and continuous in the orthogonal one. The model can be experimentally realized in several fields of physics such as optics and Bose-Einstein condensates. We demonstrate that designing an optimal relation between the nonlinearity and the linear gradient strength provides extremely long-lived Bloch oscillations with little degradation. Such robust oscillations can be observed for a broad range of parameters and even for moderate nonlinearities and large enough values of linear potential. We also present an approximate analytical description of the wave packet's evolution featuring a hybrid Bloch oscillating wave-soliton behavior that excellently corresponds to the direct numerical simulations.
我们证明，在一个离散的一维模型中，非线性可以在支持布洛赫振荡方面发挥建设性作用，而在正交方向上则是连续的。该模型可以在多个物理领域中得到实验验证，如光学和玻色-爱因斯坦凝聚体。我们证明，设计非线性和线性梯度强度之间的最佳关系可以提供几乎没有退化的极长寿命的布洛赫振荡。这种稳健的振荡可以在广泛的参数范围内观察到，甚至对于中等程度的非线性和足够大的线性势也可以观察到。我们还提出了一个波包演化的近似解析描述，具有混合的布洛赫振荡波孤子行为，与直接数值模拟非常吻合。
