# A new route to enhance the ferromagnetic transition temperature in diluted magnetic semiconductors

## TL;DR

This study uses Monte-Carlo simulations to explore how carrier density influences the ferromagnetic transition temperature in diluted magnetic semiconductors, revealing an optimal doping level and a new pathway to enhance $T_c$.

## Contribution

The paper introduces a novel understanding of the relationship between carrier density and $T_c$, proposing a new experimental route to increase ferromagnetic transition temperatures.

## Key findings

- Maximum $T_c$ occurs at a narrow carrier density range around 0.11.
- $T_c$ first increases then decreases with carrier density, showing an optimization behavior.
- An insulator-metal-insulator transition occurs across the optimal $p_{abs}$.

## Abstract

We investigate the magnetic and the transport properties of diluted magnetic semiconductors using a spin-fermion Monte-Carlo method on a 3D lattice in the intermediate coupling regime. The ferromagnetic transition temperature $T_c$ shows an optimization behavior, first increases and then decreases, with respect to the absolute carrier density $p_{abs}$ for a given magnetic impurity concentration $x$, as seen in the experiment. Our calculations also show an insulator-metal-insulator transition across the optimum $p_{abs}$ where the $T_c$ is maximum. Remarkably, the optimum $p_{abs}$ values lie in a narrow range around 0.11 for all $x$ values and the ferromagnetic $T_c$ increases with $x$. We explain our results using the polaron percolation mechanism and outline a new route to enhance the ferromagnetic transition temperature in experiments.