محمدرضا اوجي

We propose an‎d analyze a novel, highly tunable magnetic topological switch that uses a single edge-localized magnetic perturbation to drive a stanene monolayer reversibly between three distinct phases: the quantum spin Hall state, a trivial ban‎d insulator, an‎d a second-order topological insulator. By modestly varying the temperature T an‎d the magnetization orientation θ, this single localized control element implements a minimalistic, experimentally accessible scheme that endows stanene with genuine multifunctionality an‎d direct relevance for topological device architectures. To substantiate this objective, we analyze each topological phase an‎d the mechanisms driving their transitions in bulk, nanoribbon, an‎d nanoflake geometries, combining electronic-structure calculations with complementary global an‎d local diagnostics (spin-Berry curvature an‎d spin-Chern number, Wilson loops, an‎d the spectral localizer) to establish a unified bulk–boundary correspondence. For each transition this correspondence is validated by two finite-size manifestations: an effective gap closing an‎d reopening set by the edge-mode penetration depth, an‎d the emergence of quantized fractional corner charges e/2 an‎d e/4 protected by specific set of crystalline symmetries, observed across three inequivalent edge configurations.

سوييچ توپولوژيك , حالت اسپيني كوانتومي هال , عايق نواري عادي , عايق توپولوژيك مرتبه-دوم , چندمنظورگي , حالت هاي لبه , بارهاي گوشه اي كسريِ كوانتيده شده

topological switch , quantum spin Hall state , trivial band insulator , second-order topological insulator , multifunctionality , edge-mode , quantized fractional corner charges

Mohammad Reza Owji

Edris Faizabadi