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Negative Differential Resistance and Ultrahigh TMR in Altermagnetic Tunnel Junctions
Sajjan Sheoran1, Luke Keenan1, Declan Nell1
1School of Physics and CRANN Institute, Trinity College, Dublin2, Ireland.
Nano Letters
|August 12, 2026
Summary
Altermagnetic tunnel junctions exhibit unique low-bias negative differential resistance, enabling sign-inverting large tunneling magnetoresistance. This discovery highlights their potential for advanced electronic applications requiring nonlinear responses.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Spintronics
Background:
- Altermagnets offer advantages over ferromagnets in tunnel junctions, including large tunneling magnetoresistance and ultrafast switching.
- Research has primarily focused on the linear-response regime, with limited exploration of nonlinear behaviors at finite bias.
Purpose of the Study:
- To investigate the nonlinear electronic transport properties of altermagnetic tunnel junctions at finite bias.
- To predict and analyze negative differential resistance in an orbital-ordered altermagnetic material.
Main Methods:
- Density Functional Theory (DFT) calculations.
- Nonequilibrium Green's functions (NEGF) formalism.
- Simulation of current-voltage characteristics in parallel and antiparallel configurations.
Main Results:
- A pronounced low-bias negative differential resistance was predicted in KV2Se2O-based altermagnetic tunnel junctions.
- The observed negative differential resistance is attributed to the altermagnetic quasi-2D Fermi surface of KV2Se2O.
- A large tunneling magnetoresistance with sign inversion at 0.13 V was achieved due to the nonlinear response.
Conclusions:
- Altermagnetic tunnel junctions demonstrate significant nonlinear behavior at finite bias.
- The predicted negative differential resistance and sign-inverting tunneling magnetoresistance validate their potential for low-power, nonlinear electronic devices.
Keywords:
altermagnetismfirst-principles
simulationsnegative differential
resistancespin transporttunneling magnetoresistanceMore Related Videos
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