We present an experimental study of spin transport in single layer graphene using atomic sheets of hexagonal boron nitride (h-BN) as a tunnel barrier for spin injection. While h-BN is expected to be favorable for spin injection, previous experimental studies have been unable to achieve spin relaxation times in the nanosecond regime, suggesting potential problems originating from the contacts. Here, we investigate spin relaxation in graphene spin valves with h-BN barriers and observe room temperature spin lifetimes in excess of a nanosecond, which provides experimental confirmation that h-BN is indeed a good barrier material for spin injection into graphene. By carrying out measurements with different thicknesses of h-BN, we show that few layer h-BN is a better choice than monolayer for achieving high non-local spin signals and longer spin relaxation times in graphene.
@article{arxiv.1608.08688,
title = {Nanosecond spin relaxation times in single layer graphene spin valves with hexagonal boron nitride tunnel barriers},
author = {Simranjeet Singh and Jyoti Katoch and Jinsong Xu and Cheng Tan and Tiancong Zhu and Walid Amamou and James Hone and Roland Kawakami},
journal= {arXiv preprint arXiv:1608.08688},
year = {2017}
}
Comments
22 pages, 4 figures and supplementary material, [accepted for publication in Applied Physics Letters]