Low temperature spin relaxation length exceeding 3 μm in highly conductive copper channels

Date
2023-10-14
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Applied Physics
Abstract
Despite extensive studies of spin transport in metallic structures, it remains a challenge to achieve spin relaxation length well above 1 μm in metals even at low temperatures. We explore nonlocal spin transport in Cu channels with a cross section of 0.5 × 0.5 μm2, which exhibit superior values of electrical conductivity and residual resistivity ratio (RRR). Based on structures fabricated in a single batch, we found an average spin relaxation length of λCu = 3.2± 0.7 μm and an average spin relaxation time of τs = 120 ± 50 ps at 30 K. Substantial variations of λCu, RRR, and resistivity pcu are found among the structures and the three quantities correlate well to one another. The most conductive Cu channel in the batch yields λCu = 5.3 ± 0.8 μm and ts = 250± 80 ps⁠. These superior values exceed expectations for metals and can be attributed to reduced spin relaxation from grain boundaries and surfaces.
Description
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Journal of Applied Physics. The version of record is available at: https://doi.org/10.1063/5.0157839. This article will be embargoed until 10/14/2024.
Keywords
crystallographic defects, electrical conductivity, electronic transport, magnetism, drude model, phonons, spin transport effects, polycrystalline material, surface scattering
Citation
Shen, Xingyu, and Yi Ji. “Low Temperature Spin Relaxation Length Exceeding 3 μ m in Highly Conductive Copper Channels.” Journal of Applied Physics 134, no. 14 (October 14, 2023): 143902. https://doi.org/10.1063/5.0157839.