Nonlocal conductance and the detection of Majorana zero modes: Insights from von Neumann entropy

Nonlocal conductance spectroscopy in three-terminal topological superconductor hybrid setups has been proposed as a way to conclusively detect topological phase transitions involving Majorana zero modes. Topological entanglement entropy is yet another way to gauge nonlocality in connection with the bulk-boundary correspondence of a topological phase. We show that while both the entanglement entropy and the nonlocal conductance exhibit a clear topological phase-transition signature for long enough pristine nanowires, nonlocal conductance fails to signal a topological phase transition for shorter disordered wires. While recent experiments have indeed shown premature gap-closing signatures in the nonlocal conductance spectra, we demonstrate that the entanglement entropy can indeed signal a genuine transition, regardless of the constituent nonidealities in an experimental situation.

Automated summary

This article investigates the use of nonlocal conductance spectroscopy and topological entanglement entropy in detecting topological phase transitions in topological superconductors. It is found that nonlocal conductance fails to detect phase transitions for shorter disordered nanowires, while topological entanglement entropy can signal a genuine transition.