Universal transport theory for paired fractional quantum Hall states in the quantum point contact geometry
Phys. Rev. B 113, 195143 – Published 21 May, 2026
DOI: https://doi.org/10.1103/nqsj-hl9z
Abstract
Even-denominator fractional quantum Hall (FQH) states can be viewed as topological superconductors of composite fermions, supporting a charged chiral mode and neutral Majorana modes set by the Chern number . Despite ongoing efforts, distinguishing the many competing paired phases remains an open problem. In this work, we propose a unified theory of charge transport across a quantum point contact for general paired FQH states described by an conformal field theory. We derive the boundary effective action for an arbitrary number of Majorana fermions and develop a nonperturbative instanton approximation to describe tunneling processes. We establish a weak-strong duality relating strong quasiparticle tunneling to weak electron tunneling. We calculate the scaling dimensions of the tunneling operators and demonstrate that while the weak-coupling fixed point is generally unstable, the strong-coupling fixed point is stable for physically relevant filling fractions and number of Majorana fermions. These transport exponents provide a distinct experimental fingerprint to identify the topological phases of even-denominator FQH states.