Nanosecond Reversal of Three-Terminal Spin Hall Effect Memories Sustained at Cryogenic Temperatures

TL;DR

This paper demonstrates nanosecond-scale switching of three-terminal spin Hall effect magnetic tunnel junctions at cryogenic temperatures, showing potential for high-speed cryogenic memory in superconducting computing.

Contribution

It provides the first characterization of ultrafast cryogenic SHE-MTJ switching with reliable performance at 3 K, surpassing macrospin model expectations.

Findings

Achieved <10^{-6} bit error rate with <10 ns pulses.

Demonstrated reliable switching with 1 ns pulses at cryogenic temperatures.

Validated performance with exponentially decaying pulses suitable for realistic memory circuits.

Abstract

We characterize the nanosecond pulse switching performance of the three-terminal magnetic tunnel junctions (MTJs), driven by the spin Hall effect (SHE) in the channel, at a cryogenic temperature of 3 K. The SHE-MTJ devices exhibit reasonable magnetic switching and reliable current switching by as short pulses as 1 ns of $<10^{12}$ A/m$^{2}$ magnitude, exceeding the expectation from conventional macrospin model. The pulse switching bit error rates reach below $10^{-6}$ for < 10 ns pulses. Similar performance is achieved with exponentially decaying pulses expected to be delivered to the SHE-MTJ device by a nanocryotron device in parallel configuration of a realistic memory cell structure. These results suggest the viability of the SHE-MTJ structure as a cryogenic memory element for exascale superconducting computing systems.