Low voltage control of ferromagnetism in a semiconductor p-n junction

TL;DR

This paper demonstrates that low-voltage electrical pulses can induce persistent magnetization switching in a semiconductor ferromagnetic p-n junction, bridging semiconductor charge control and spintronics for energy-efficient magnetic device applications.

Contribution

It introduces a novel method for controlling ferromagnetism electrically at low voltages in a semiconductor p-n junction, combining charge depletion with spintronics.

Findings

Persistent magnetization switching with a few volts electrical pulses.

Electrical control of ferromagnetism in all-semiconductor devices.

Potential for low-power spintronic applications.

Abstract

The concept of low-voltage depletion and accumulation of electron charge in semiconductors, utilized in field-effect transistors (FETs), is one of the cornerstones of current information processing technologies. Spintronics which is based on manipulating the collective state of electron spins in a ferromagnet provides complementary technologies for reading magnetic bits or for the solid-state memories. The integration of these two distinct areas of microelectronics in one physical element, with a potentially major impact on the power consumption and scalability of future devices, requires to find efficient means for controlling magnetization electrically. Current induced magnetization switching phenomena represent a promising step towards this goal, however, they relay on relatively large current densities. The direct approach of controlling the magnetization by low-voltage charge depletion effects is seemingly unfeasible as the two worlds of semiconductors and metal ferromagnets are separated by many orders of magnitude in their typical carrier concentrations. Here we demonstrate that this concept is viable by reporting persistent magnetization switchings induced by short electrical pulses of a few volts in an all-semiconductor, ferromagnetic p-n junction.