Spin Diode Based on Fe/MgO Double Tunnel Junction

TL;DR

This paper reports a novel Fe/MgO-based double tunnel junction functioning as a highly effective spin diode with record-high magneto-resistance and strong diode effect, promising for advanced memory and logic devices.

Contribution

It introduces a new spin diode device based on Fe/MgO double tunnel junction with record-high magneto-resistance and combined diode effects, demonstrating potential for spintronic applications.

Findings

Record high magneto-resistance (~4000%)

Near perfect spin-valve effect and diode effect (~100)

Resonant tunneling through discrete states in ferromagnetic layer

Abstract

We demonstrate a spin diode consisting of a semiconductor free nano-scale Fe/MgO-based double tunnel junction. The device exhibits a near perfect spin-valve effect combined with a strong diode effect. The mechanism consistent with our data is resonant tunneling through discrete states in the middle ferromagnetic layer sandwiched by tunnel barriers of different spin-dependent transparency. The observed magneto-resistance is record high, ~4000%, essentially making the structure an on/off spin-switch. This, combined with the strong diode effect, ~100, offers a new device that should be promising for such technologies as magnetic random access memory and re-programmable logic.