# Wurtzite spin lasers

## TL;DR

This paper develops a theoretical framework for wurtzite spin lasers, specifically (In,Ga)N-based quantum wells, revealing how spin polarization influences gain and lasing thresholds, thus opening new avenues for spin laser control.

## Contribution

It provides the first theoretical description of wurtzite spin lasers, combining microscopic spin-dependent gain calculations with rate equations, highlighting unique spin control mechanisms.

## Key findings

- Gain asymmetry can change sign with carrier density.
- Lasing threshold reduction depends nonmonotonically on electron spin polarization.
- Simultaneous electron and hole spin polarizations are supported in wurtzite semiconductors.

## Abstract

Semiconductor lasers are strongly altered by adding spin-polarized carriers. Such spin lasers could overcome many limitations of their conventional (spin-unpolarized) counterparts. While the vast majority of experiments in spin lasers employed zinc-blende semiconductors, the room temperature electrical manipulation was first demonstrated in wurtzite GaN-based lasers. However, the underlying theoretical description of wurtzite spin lasers is still missing. To address this situation, focusing on (In,Ga)N-based wurtzite quantum wells, we develop a theoretical framework in which the calculated microscopic spin-dependent gain is combined with a simple rate equation model. A small spin-orbit coupling in these wurtzites supports simultaneous spin polarizations of electrons and holes, providing unexplored opportunities to control spin lasers. For example, the gain asymmetry, as one of the key figures of merit related to spin amplification, can change the sign by simply increasing the carrier density. The lasing threshold reduction has a nonmonotonic depenedence on electron spin polarization, even for a nonvanishing hole spin polarization.