Here, we propose that Floquet engineering offers a strategy to realize the nonequilibrium quantum anomalous Hall effect (QAHE) with tunable Chern number. Using first-principles calculations and Floquet theorem, we unveil that QAHE related to valley polarization (VP-QAHE) is formed from the hybridization of Floquet sidebands in the two-dimensional family Si (M = Mo, W, V; = N, P, As) by irradiating circularly polarized light (CPL). Through the tuning of frequency, intensity, and handedness of CPL, the Chern number of VP-QAHE is highly tunable and up to = ±4, which attributes to light-induced trigonal warping and multiple-band inversion at different valleys. The chiral edge states and quantized plateau of Hall conductance are visible inside the global band gap, thereby facilitating the experimental measurement. Our work not only establishes Floquet engineering of nonequilibrium VP-QAHE with tunable Chern number in realistic materials but also provides an avenue to explore emergent topological phases under light irradiation.
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Article Synopsis
- Recent studies focus on creating hybrid systems of magnets and superconductors that exhibit topological superconductivity.
- The research demonstrates that using Floquet engineering with antiferromagnetic layers and s-wave superconductors can induce chiral topological superconductivity through light interaction that disrupts time-reversal symmetry.
- The ability to control these topological phases with elliptically polarized light offers a novel way to manipulate superconducting properties through related changes in valley pairs, making this approach promising for experimental exploration.
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