Strategies and tolerances of spin transfer torque switching

TL;DR

This paper compares different spin transfer torque switching schemes for nanomagnetic memories, demonstrating that perpendicular polarization with short pulses is more efficient and tolerant than collinear in-plane polarization.

Contribution

It provides a comparative analysis of switching schemes using macrospin and micromagnetic simulations, highlighting the advantages of perpendicular polarization and damping effects.

Findings

Perpendicular polarization switching requires less time and energy.

Increased damping improves switching tolerances.

Perpendicular switching is superior to other memory types.

Abstract

Schemes of switching nanomagnetic memories via the effect of spin torque with various polarizations of injected electrons are studied. Simulations based on macrospin and micromagnetic theories are performed and compared. We demonstrate that switching with perpendicularly polarized current by short pulses and free precession requires smaller time and energy than spin torque switching with collinear in plane spin polarization; it is also found to be superior to other kinds of memories. We study the tolerances of switching to the magnitude of current and pulse duration. An increased Gilbert damping is found to improve tolerances of perpendicular switching without increasing the threshold current, unlike in plane switching.