Tailoring metal-insulator transitions and band topology via off-resonant periodic drive in an interacting triangular lattice

Autor: Anamitra Mukherjee, Priyanka Mohan, Sayan Jana, Arijit Saha
Rok vydání: 2020
Předmět:
Zdroj: Physical Review B. 101
ISSN: 2469-9969
2469-9950
DOI: 10.1103/physrevb.101.115428
Popis: A triangular lattice with onsite Coulomb interaction $U$ present only on one sub-lattice, is periodically driven by electromagnetic field with a frequency $\Omega \gg (t,~U)$ 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 neighbour hopping parameters. For $U=0$, the driving acts like an emergent intrinsic spin-orbit coupling term and stabilises three dispersive bands with the lower and upper bands having non zero Chern numbers. Within a slave rotor mean field theory, we show that while $U$ freezes out charge fluctuations on the interacting sub-lattice, it does not open up a charge gap without the external drive. In 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 sub-lattice stabilizes an emergent, low energy \textit{half filled non-interacting Kane-Mele model}, whose band gaps can be tuned by varying $A$. In this limit, we show that the external drive provides an handle to engineer periodic band inversions at specific values of $A$ accompanied by topological phase transitions that are characterised by swapping of band Chern numbers.
Comment: This is the published version
Databáze: OpenAIRE