2025/11/10 by Fei Yang, Dong E. Liu, Yang, Fei +1
Physics and Astronomy · #Topological Materials and Phenomena #Quantum and electron transport phenomena #Quantum many-body systems
paper · pdf · doi:10.48550/arxiv.2511.08635
Conventional wisdom holds that static disorder is indispensable to the integer quantum Hall effect, underpinning both quantized plateaus and the plateau-plateau transition. We show that pure dephasing, without elastic disorder, is sufficient to generate the same θ driven criticality. Starting from a Keldysh formulation, we derive an open system nonlinear σ model (NLσM) for class A with a topological θ term but no Cooperon sector, and we demonstrate that nonperturbative instantons still govern a two parameter flow of (σxx,σxy). Evaluating θ in a dephasing quantum anomalous Hall setting, we predict a quantum Hall critical point at σxy=1/2 with finite σxx the hallmark of the integer quantum Hall universality class realized without Anderson localization. Boundary driven simulations of the QiWuZhang model with local dephasing confirm this prediction and provide an experimentally aligned protocol to extract (σxx,σxy) from Hall potential maps. By establishing dephasing as a self contained route to Hall criticality, our framework reframes plateau physics in open solid state and cold atom platforms and offers practical diagnostics for topological transport in nonunitary matter.