Altermagnets demonstrate significant potential in spintronics due to their unique non-relativistic spin-splitting properties, yet altermagnetic devices still face challenges in efficiently switching logic states. Here, we report electrostatically controllable spin-momentum locking in bilayer Cr2SeO and design a dual-gate altermagnetic tunnel junction (AMTJ), which can switch between high and low resistance states without switching the N\'eel vector. First-principles calculations demonstrate that vertical electric field can induce significant spin splitting in bilayer Cr2SeO. Reversing the electric field direction can alter the spin-momentum locking in bilayer Cr2SeO. Leveraging this electric-field-tunable spin splitting, the dual-gate AMTJ exhibits an ultrahigh tunneling magnetoresistance (TMR) ratio of 107. This work provides theoretical support for the design of fully electrically controlled AMTJs and demonstrates their great potential for applications in spintronic devices.
@article{arxiv.2512.23253,
title = {A Dual-Gate Altermagnetic Tunnel Junction Based on Bilayer Cr$_{2}$SeO},
author = {Yunfei Gao and Aolin Li and Zesen Fu and Bei Zhang and Haiming Duan and Fangping Ouyang},
journal= {arXiv preprint arXiv:2512.23253},
year = {2026}
}