# Inverse Edelstein effect of the surface states of a topological insulator

## TL;DR

This paper develops a semiclassical theory for the inverse Edelstein effect in topological insulator surface states, revealing universal size-dependent efficiency ratios that approach known limits in ballistic and diffusive regimes.

## Contribution

It introduces a comprehensive semiclassical model for IEE in topological insulator surfaces applicable across transport regimes.

## Key findings

- IEE efficiency ratio depends universally on sample size
- Ratio approaches π/4 in ballistic limit
- Ratio approaches 1 in diffusive limit

## Abstract

The surface states of three-dimensional topological insulators posses the unique property of spin-momentum interlocking. This property gives rise to the interesting inverse Edelstein effect (IEE), in which an applied spin bias $\mu$ is converted to a measurable charge voltage difference $V$. We develop a semiclassical theory for the IEE of the surface states of $\text{Bi}_2\text{Se}_3$ thin films, which is applicable from the ballistic regime to diffusive regime. We find that the IEE efficiency ratio $\gamma=V/\mu$ exhibits universal dependence on sample size, and approaches $\pi/4$ in the ballistic limit and $1$ in the diffusive limit.