Zero-dimensional spin accumulation and spin dynamics in a mesoscopic metal island

TL;DR

This study demonstrates uniform electron spin accumulation in a mesoscopic aluminium island at various temperatures, revealing insights into spin dynamics and relaxation times through four-terminal measurements and spin precession analysis.

Contribution

It presents the first measurement of uniform spin accumulation in a mesoscopic metal island with detailed control of magnetization directions and spin precession analysis.

Findings

Uniform spin accumulation exceeds ohmic resistance

Spin precession confirms uniformity and allows relaxation time extraction

Spin relaxation time measured accurately in a mesoscopic aluminium island

Abstract

We have measured electron spin accumulation at 4.2 K and at room temperature in an aluminium island with all dimensions (400nm x 400nm x 30nm) smaller than the spin relaxation length. For the first time, we obtain uniform spin accumulation in a four-terminal lateral device with a magnitude exceeding the ohmic resistance in the island. By controlling the magnetisation directions of the four magnetic electrodes that contact the island, we have performed a detailed study of the spin accumulation. Spin precession measurements confirm the uniformity of our system and provide an accurate method to extract the spin relaxation time.