Majorana edge reconstruction resolves the ν = 5/2 thermal Hall puzzle, study shows
A theoretical model explains why fractional quantum Hall state transport matches PH-Pfaffian observations without fine-tuning.
Physicists have proposed a theoretical mechanism to reconcile experimental thermal transport observations with numerical models of the fractional quantum Hall effect at filling factor ν = 5/2, according to Proceedings of the National Academy of Sciences pnas.org
Proceedings of the National Academy of Sciencespnas.orgOpen source ↗. Thermal Hall conductance κ at this plateau is quantized in half-integer multiples of κ 0 = π 2 k B 2 T / 3 h, signaling neutral Majorana edge modes associated with bulk non-Abelian anyons.
Previous experiments identified a half-integer value corresponding to the PH-Pfaffian topological state. Numerical calculations, however, consistently favor either the Pfaffian or Anti-Pfaffian configurations, creating a persistent theoretical discrepancy. Previous attempts to bridge this gap either required precise parameter fine-tuning or were contradicted by subsequent measurements.
To resolve the contradiction, the researchers evaluated physically realistic edges using density-matrix renormalization group simulations combined with analytic calculations of the edge structure. Their findings demonstrate that edge reconstruction confined strictly to the neutral Majorana sector screens the underlying bulk state. As a result, a bulk Pfaffian or Anti-Pfaffian system generates transport signatures identical to those of a PH-Pfaffian, providing a natural mechanism consistent with experimental data.
