Gate-tunable spin exclusive or operation in a silicon-based spin device at room temperature

TL;DR

This paper demonstrates room temperature operation of a silicon-based spin XOR gate with reconfigurable logic, showing high charge current detection and gate voltage modulation, advancing spintronic logic device technology.

Contribution

The work introduces a silicon-based spin XOR gate operable at room temperature with high charge current detection and reconfigurable logic capabilities.

Findings

Achieved the highest charge current of 0.94 nA in spin XOR gates.

Demonstrated gate voltage modulation enabling multiple device operation.

Validated the XOR behavior with a spin drift-diffusion model.

Abstract

Room temperature operation of a spin exclusive or (XOR) gate was demonstrated in lateral spin valve devices with nondegenerate silicon (Si) channels. The spin XOR gate is a fundamental part of the magnetic logic gate (MLG) that enables reconfigurable and nonvolatile NAND or OR operation in one device. The device for the spin XOR gate consists of three iron (Fe)/cobalt (Co)/magnesium oxide (MgO) electrodes, i.e., two input and one output electrodes. Spins are injected into the Si channel from the input electrodes whose spin angular momentum corresponds to the binary input 1 or 0. The spin drift effect is controlled by a lateral electric field in the Si channel to adjust the spin accumulation voltages under two different parallel configurations, corresponding to (1, 1) and (0, 0), so that they exhibit the same value. As a result, the spin accumulation voltage detected by the output electrode exhibits three different voltages, represented by an XOR gate. The one-dimensional spin drift-diffusion model clearly explains the obtained XOR behavior. Charge current detection of the spin XOR gate is also demonstrated. The detected charge current has a maximum of 0.94 nA, the highest value in spin XOR gates reported thus far. Furthermore, gate voltage modulation of the spin XOR gate is also demonstrated, which enables operation of multiple MLG devices.