Jun-Xiao Hui | Searcharxiv

arXiv2026

Fractionalized anyons in counterflowing Quantum Hall Liquids

A key property of topologically ordered systems, such as Quantum Hall states, is the existence of excitations obeying fractional quantum statistics - anyons. We develop a theory for multicomponent counterflow states where an ordinary Laughlin quasiparticle can split into fractional vortices carrying fractions of its charge and statistical angle. There are two phases, separated by a quantum phase transition, where in the first, although observable, the fractionalized charges are asymptotically confined. In the second phase, they are unconfined anyons and the topological order is different from that of the Laughlin state.

cond-mat.str-el↗

arXiv2026

Nonreciprocal perfect Coulomb drag in electron-hole bilayers: coherent exciton superflow as a diode

Distinguishing an exciton condensate from an excitonic gas or insulator remains a fundamental challenge, as both phases feature bound electron-hole pairs but differ only by the emergence of macroscopic phase coherence. Here, we theoretically propose that a spin-orbit-coupled bilayer system can host a finite-momentum exciton condensate exhibiting a nonreciprocal perfect Coulomb drag -- the coherent-exciton diode effect. This effect arises from the simultaneous breaking of inversion and time-reversal symmetries in the exciton condensate, resulting in direction-dependent critical counterflow currents. The resulting nonreciprocal perfect Coulomb drag provides a clear and unambiguous transport signature of phase-coherent exciton condensation, offering a powerful and experimentally accessible approach to identify, probe, and control exciton superfluidity in solid-state platforms.

cond-mat.mes-hall↗