# Lateral p-n Junction in an Inverted InAs/GaSb Double Quantum Well

## TL;DR

This study investigates a lateral p-n junction in an inverted InAs/GaSb double quantum well, revealing diode-like behavior at zero magnetic field and complex edge state interactions under magnetic fields, advancing topological state research.

## Contribution

It demonstrates the transport properties of a lateral p-n junction in InAs/GaSb quantum wells and explores edge state interactions in the quantum Hall regime, providing insights for topological state transitions.

## Key findings

- Diodelike behavior at zero magnetic field.
- Edge state mixing and full equilibration at high magnetic fields.
- Potential for probing topological quantum phase transitions.

## Abstract

We present transport measurements on a lateral p-n junction in an inverted InAs/GaSb double quantum well at zero and nonzero perpendicular magnetic fields. At a zero magnetic field, the junction exhibits diodelike behavior in accordance with the presence of a hybridization gap. With an increasing magnetic field, we explore the quantum Hall regime where spin-polarized edge states with the same chirality are either reflected or transmitted at the junction, whereas those of opposite chirality undergo a mixing process, leading to full equilibration along the width of the junction independent of spin. These results lay the foundations for using p-n junctions in InAs/GaSb double quantum wells to probe the transition between the topological quantum spin Hall and quantum Hall states.