# The Ferromagnetism in the Vicinity of Lifshitz Topological Transitions

## TL;DR

This paper investigates how the ferromagnetic transition temperature in a quasi-2D hole gas varies near Lifshitz topological transitions, showing it can be significantly tuned by small changes in gate voltage.

## Contribution

It reveals the strong dependence of Curie temperature on hole chemical potential near Lifshitz transitions in quantum wells, providing a way to control ferromagnetism electrically.

## Key findings

- Curie temperature varies significantly near Lifshitz points.
- Small gate voltage changes can double the Curie temperature.
- Model predicts tunable ferromagnetism in quantum well devices.

## Abstract

We show that the critical temperature of a ferromagnetic phase transition in a quasi-two-dimensional hole gas confined in a diluted magnetic semiconductor quantum well strongly depends on the hole chemical potential and hole density. The significant variations of the the Curie temperature occur close to the Lifshitz topological transition points where the hole Fermi surface acquires additional components of topological connectivity due to the filling of excited size-quantization subbands. The model calculations demonstrate that the Curie temperature can be doubled by a small variation of the gate voltage for the CdMnTe/CdMgTe quantum well based device.