Antiferromagnetic parametric resonance driven by voltage-controlled magnetic anisotropy

TL;DR

This paper theoretically demonstrates that voltage-controlled magnetic anisotropy (VCMA) can efficiently excite and manipulate antiferromagnetic resonant modes, enabling low-energy electrical control of AFM dynamics with enhanced coupling efficiency.

Contribution

It introduces VCMA as a highly efficient method for parametric resonance in antiferromagnets, surpassing traditional magnetic field techniques and enabling zero-field resonance.

Findings

VCMA experiences exchange enhancement, increasing efficiency by 10-100 times.

VCMA enables zero-field parametric resonance in AFMs with out-of-plane easy axis.

VCMA is the most promising method for coherent AFM order manipulation.

Abstract

Voltage controlled magnetic anisotropy (VCMA) is a low-energy alternative to manipulate the ferromagnetic state, which has been recently considered also in antiferromagnets (AFMs). Here, we theoretically demonstrate that VCMA can be used to excite linear and parametric resonant modes in easy-axis AFMs with perpendicular anisotropy, thus opening the way for an efficient electrical control of the Neel vector, and for detection of high-frequency dynamics. Our work leads to two key results: (i) VCMA parametric pumping experiences the so-called exchange enhancement of the coupling efficiency and, thus, is 1-2 orders of magnitude more efficient than microwave magnetic fields or spin-orbit-torques, and (ii) it also allows for zero-field parametric resonance, which cannot be achieved by other parametric pumping mechanisms in AFMs with out-of-plane easy axis. Therefore, we demonstrate that the VCMA parametric pumping is the most promising method for coherent excitation and manipulation of AFM order in perpendicular easy-axis AFMs.