Topological Charge-2ne Superconductors

TL;DR

This paper develops a comprehensive theoretical framework for topological charge-2ne superconductors, revealing their unique properties, edge states, and potential for experimental detection, expanding understanding of unconventional superconducting phases.

Contribution

It introduces a unified wavefunction and field theory approach to topological charge-2ne superconductors derived from charge-2e systems and quantum Hall states, highlighting their nonabelian topological orders.

Findings

Constructs bulk and edge theories for charge-2ne superconductors.

Identifies fermionic nonabelian topological orders in these phases.

Provides insights for experimental detection via quasiparticle interferometry.

Abstract

Charge-$4e$ superconductors are phases where quartets of electrons condense in the absence of Cooper pairing condensation. They exhibit distinctive signatures including fractional flux quantization and anomalous Josephson effects, and are actively being explored in strongly correlated systems, such as moir\'e materials. In this work we develop a general framework for topological charge-$2ne$ superconductors based on both wavefunction and field theory approaches. In particular, we generate topological charge-$2ne$ superconductors from charge-$2e$ ingredients, and by breaking the charge $U(1)$ symmetry in certain classes of quantum Hall states, in both spinless and spinful systems. Via bulk-edge correspondence, we further construct the corresponding edge conformal field theory and bulk topological quantum field theory for topological charge-$2ne$ superconductors that suggests fermionic nonabelian topological orders. Our results provide a unified low-energy description of the topological charge-$2ne$ superconductivity, offer a concrete platform for studying symmetry breaking and enrichment in interacting topological phases of matter, and have direct implications for experimental probes such as quasiparticle interferometry.