2024/12/23 by Benhaida, O., Saidi, E. H., Drissi, L. B. +1
#FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Other Condensed Matter (cond-mat.other)
paper · doi:10.48550/arxiv.2412.17763
We investigate the topological properties of photon-dressed energy bands in bilayer α-T3 lattices under off-resonant circularly polarized light, focusing on aligned and cyclic stacking configurations. Analytical expressions for quasi-energy bands are derived for aligned stacking, while numerical results address cyclic stacking at Dirac points. Circularly polarized light breaks the time-reversal symmetry, lifting the degeneracies at the intersections ta,c, leading to the appearance of a Haldane-type Chern insulator in the absence of a magnetic field . At α= 1/√(2), orbital magnetic moments of corrugated and flat bands exhibit opposite signs, as do their Berry curvatures. For 0 < α< 1, light-induced band deformations near Dirac points create gaps in the quasi-energy spectrum, where the chemical potential modulates orbital magnetization. Linear magnetization variations align with Chern numbers, yielding quantized anomalous Hall conductivity across stacking types. Notable particle-hole symmetry breaking within 0 < α< 1 suggests applications in valley caloritronics and quantum sensing. At α= 1, flat and corrugated bands remain undistorted; while the flat band contributes no Berry curvature, it produces a finite negative orbital magnetic moment, contrasting with the positive moment of the corrugated band.