Enhanced Bulk-Edge Coulomb Coupling in Fractional Fabry-Perot Interferometers.

Area of Science:

• Condensed Matter Physics
• Quantum Hall Effect
• Topological Quantum Computing

Background:

• Recent experiments using Fabry-Perot (FP) interferometry claim the ν=5/2 quantum Hall state exhibits non-Abelian topological order.
• These experimental claims appear inconsistent with theoretical models that neglect bulk-edge Coulomb coupling and Majorana tunneling.

Purpose of the Study:

• To reexamine the theoretical model of FP devices used in quantum Hall state experiments.
• To investigate the role of Coulomb coupling in interpreting experimental results for the ν=5/2 state.

Main Methods:

• Theoretical reexamination of Fabry-Perot (FP) device physics.
• Modeling the influence of bulk-edge Coulomb coupling on fractional quantum Hall plateaus.
• Analysis of experimental data considering both Coulomb effects and non-Abelian braiding signatures.

Main Results:

• A moderate Coulomb coupling can significantly impact certain fractional plateaus while minimally affecting others.
• The developed model successfully explains experimental data across a wide range of plateaus.
• Experimental observations are consistent with the ν=5/2 state exhibiting Moore-Read topological order.

Conclusions:

• The study suggests that Coulomb effects, rather than non-Abelian braiding, might be responsible for the observed "even-odd effect" in FP interferometry experiments.
• Further theoretical and experimental work is needed to disentangle Coulomb effects from genuine non-Abelian braiding signatures in the ν=5/2 quantum Hall state.