Motivated by recent experimental progress on measuring various correlation functions in systems of ultracold atoms in optical lattices, we study properties of the Bose-Hubbard model in external synthetic magnetic field to describe transport phenomena in a multiband strongly interacting bosonic systems. We calculate the conductivity both in the Mott insulator and superfluid phases and investigate its two main contributions: intra- and interband. It appears that the interband processes dominate the transport properties by at least an order of magnitude. Also, at finite temperatures, additional transport channels appear due to coupling of the thermally excited particles or holes to the external field.

中文翻译：

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相互作用强的玻色子的带内和带间电导率

受最近测量光学晶格中超冷原子系统中各种相关函数的实验进展的启发，我们研究了外部合成磁场中的Bose-Hubbard模型的性质，以描述在多频带强相互作用的玻色子系统中的传输现象。我们计算莫特绝缘子相和超流体相的电导率，并研究其两个主要贡献：带内和带间。看来带间过程至少在一个数量级上主导着传输性能。同样，在有限的温度下，由于热激发的颗粒或空穴与外部场的耦合，出现了额外的传输通道。