Nanosecond spin lifetimes in single- and few-layer graphene-hBN heterostructures at room temperature

TL;DR

This study introduces a novel fabrication method for graphene spin-valve devices, achieving nanosecond spin lifetimes and long spin diffusion lengths at room temperature, advancing the potential for spintronic applications.

Contribution

The paper presents a new fabrication approach that significantly enhances spin and charge transport in graphene-hBN heterostructures at room temperature.

Findings

Nanosecond spin lifetimes in graphene devices at room temperature.

Spin diffusion lengths up to 10 micrometers.

Carrier mobilities exceeding 20,000 cm²/Vs.

Abstract

We present a new fabrication method of graphene spin-valve devices which yields enhanced spin and charge transport properties by improving both the electrode-to-graphene and graphene-to-substrate interface. First, we prepare Co/MgO spin injection electrodes onto Si$^{++}$/SiO$_2$. Thereafter, we mechanically transfer a graphene-hBN heterostructure onto the prepatterned electrodes. We show that room temperature spin transport in single-, bi- and trilayer graphene devices exhibit nanosecond spin lifetimes with spin diffusion lengths reaching 10$\mu$m combined with carrier mobilities exceeding 20,000 cm$^2$/Vs.