Two-dimensional alternating ferrimagnetism with strain-controlled half-metallic state and valley polarization

TL;DR

This paper introduces 2D alternating ferrimagnetism, a novel magnetic phase combining net magnetization with momentum-dependent spin splitting, tunable by strain and promising for spintronic devices.

Contribution

It proposes a new 2D magnetic phase, alternating ferrimagnetism, merging altermagnetic and ferromagnetic properties with strain-controlled functionalities.

Findings

Stable alternating ferrimagnetism demonstrated in strained Cr-doped V2Te2O.

Strain allows tuning of net magnetization and reverses half-metallicity.

Long-range magnetic order persists above room temperature.

Abstract

The discovery of altermagnetism offers new opportunities for exploring novel quantum states and developing spintronic devices for enabling momentum dependent spin splitting in compensated systems, while zero net magnetization limit its manipulability using conventional magnetic method. Here, we propose 2D alternating ferrimagnetism,a phase merging alternating momentum dependent spin splitting with a finite net magnetization. A tight binding model reveals that alternating ferrimagnetism originates from uncompensated magnetization in altermagnets, facilitating concurrent net magnetization and alternating spin splitting. First principles calculations and Monte Carlo simulations demonstrate stable alternating ferrimagnetism in strained and Cr substiting V2Te2O, which exhibit strain tunable net magnetization, reversable half metallicity and valley polarization, accompanied by long range magnetic order above room temperature. By combining altermagnetic and ferromagnetic properties, alternating ferrimagnetism expand the 2D magnetism landscape and offer pathways for energy efficient spintronic applications.