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Tailoring metal-insulator transitions and band topology via off-resonant periodic drive in an interacting triangular lattice
Physical Review B ( IF 3.2 ) Pub Date : 2020-03-27 , DOI: 10.1103/physrevb.101.115428
Sayan Jana , Priyanka Mohan , Arijit Saha , Anamitra Mukherjee

A triangular lattice with onsite Coulomb interaction U present only on one sublattice is periodically driven by electromagnetic field with a frequency Ω(t,U) at half filling. In this high frequency limit, the electromagnetic vector potential, with an amplitude A, modifies the bare hopping and generates new next nearest neighbor hopping parameters. For U=0, the driving acts like an emergent intrinsic spin-orbit coupling term and stabilizes three dispersive bands with the lower and upper bands having nonzero Chern numbers. Within a slave rotor mean field theory, we show that while U freezes out charge fluctuations on the interacting sublattice, it does not open up a charge gap without the external drive. In the presence of the drive, and small U, the system exhibits repeated metal-insulator transitions as a function of the amplitude A. For large U, we establish that the freezing of charge fluctuations on the interacting sublattice stabilizes an emergent, low energy half filled noninteracting Kane-Mele model, whose band gaps can be tuned by varying A. In this limit, we show that the external drive provides a handle to engineer periodic band inversions at specific values of A accompanied by topological phase transitions that are characterized by swapping of band Chern numbers.

中文翻译:

通过相互作用的三角晶格中的非共振周期驱动来定制金属-绝缘体跃迁和能带拓扑

具有现场库仑相互作用的三角形晶格 ü 仅存在于一个子晶格上的电磁场周期性地被具有一定频率的电磁场驱动 ΩŤü在一半的填充。在这个高频极限中,电磁矢量势一种,修改裸跳并生成新的下一个最近邻居跳变参数。对于ü=0,驱动就像一个新兴的固有自旋轨道耦合项,并稳定了三个色散带,其上下带具有非零的Chern数。在从动转子均场理论中,我们证明了ü冻结了相互作用的子晶格上的电荷波动,没有外部驱动器就不会打开电荷间隙。在驱动器的存在下,小ü,系统表现出重复的金属-绝缘体转变,这是振幅的函数 一种。对于大ü,我们建立了相互作用的子晶格上电荷波动的冻结稳定了一个新兴的,低能量的半填充非相互作用的Kane-Mele模型,该模型的带隙可以通过改变来调整一种。在此限制下,我们表明外部驱动器可为特定频率下的周期性频带反转工程设计提供一个句柄。一种 伴随着以相切带数交换为特征的拓扑相变。
更新日期:2020-03-27
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