Quantized Transport of ν=2/3 Fractional Quantum Hall Edge with Disordered Superconducting Proximity

Area of Science:

• Condensed Matter Physics
• Quantum Phenomena

Background:

• Proximity of superconductors (SC) to Quantum Hall edge states usually leads to nonquantized electron-to-hole conversion.
• This is often attributed to nonuniversal SC couplings and disorder effects.

Purpose of the Study:

• Investigate the impact of disordered SC couplings on fractional quantum Hall (FQH) edge states at ν=2/3.
• Explore the possibility of quantized transport signatures beyond Hall conductance.

Main Methods:

• Theoretical analysis of counterpropagating edge modes in FQH states coupled to a superconductor.
• Modeling the effect of disordered SC couplings on edge state reconstruction.

Main Results:

• Disordered SC couplings can stabilize an infinite set of phases in ν=2/3 FQH edge states.
• These phases exhibit quantized electron-to-hole conversion probability.
• A quantized downstream resistance R_{d}=h/(2q_{N}^{2}e^{2}) is predicted, with |q_{N}|=1, 4, 15, etc.

Conclusions:

• Disorder can lead to novel, stable phases in FQH edge states with SC proximity.
• The predicted quantized resistance serves as a distinct signature of these phases.
• Findings may extend to other systems like fractional Chern insulators.