Effects of light on quantum phases and topological properties of two-dimensional Metal-organic frameworks

Abstract

Periodically driven nontrivial quantum states open another door to engineer topological phases in solid systems by light. Here we show, based on the Floquet-Bloch theory, that the on-resonant linearly and circularly polarized infrared light brings in the exotic Floquet quantum spin Hall state and half-metal in two-dimensional Metal-organic frameworks (2D MOFs) because of the unbroken and broken time-reversal symmetry, respectively. We also observe that the off-resonant light triggers topological quantum phase transitions and induces semimetals with pseudospin-1 Dirac-Weyl fermions via the photon-dressed topological band structures of 2D MOFs. This work paves a way to design light-controlled spintronics and optoelectronics based on 2D MOFs.

Universal driving protocol for symmetry-protected Floquet topological phases

“…Topological phases have become a central topic of condensed matter research over the last few decades [1][2][3][4][5][6]. Recently, topological phases in periodically driven systems [7][8][9][10][11][12][13] have attracted increasing interest, including the anomalous Floquet topological insulators that exhibit a non-trivial topological phase although each of the individual Floquet bands is topologically trivial [14]. Photonic lattices of evanescently coupled waveguides are especially well suited for the realization of these new topological phases [15,16].…”

Behavior of Floquet Topological Quantum States in Optically Driven Semiconductors

“…In non-equilibrium systems, it has been shown that time-periodic perturbations can induce topological properties in conventional insulators [17][18][19][20] which are trivial in equilibrium otherwise. Floquet topological insulators include a very broad range of physical solid state and atomic realizations, driven at resonance or off-resonance.…”

Behavior of Floquet Topological Quantum States in Optically Driven Semiconductors

“…Already topological insulators in solid-state devices such as HgTe/CdTe quantum wells [12,13], as well as topological Dirac insulators such as Bi 2 Te 3 and Bi 2 Sn 3 [14][15][16] were groundbreaking discoveries in the search for the unique properties of topological phases and their technological applications. In non-equilibrium systems it has been shown that time-periodic perturbations can induce topological properties in conventional insulators [17][18][19][20] which are trivial in equilibrium otherwise. Floquet Centrosymmetric, cubic, rocksalt configuration (Rochelle salt) [63][64][65].…”