Multi-terminal spin-dependent transport in ballistic carbon nanotubes

TL;DR

This paper theoretically investigates nonlocal spin transport in ballistic carbon nanotubes with ferromagnetic and normal-metal contacts, revealing hysteretic behavior and resonance-enhanced magnetic signals in the few-channel coherent regime.

Contribution

It introduces a theoretical model for spin transport in ballistic nanotubes, highlighting resonance effects and hysteresis unique to the few-channel regime.

Findings

Hysteretic behavior observed when switching magnetization configurations.

Resonance effects significantly amplify magnetic signals in the coherent limit.

Results differ markedly from multichannel diffusive incoherent regime experiments.

Abstract

We study theoretically nonlocal spin transport in a ballistic carbon nanotube contacted to two ferromagnetic leads and two normal-metal leads. When the magnetizations of the two ferromagnets are changed from a parallel to an antiparallel configuration, the circuit shows a hysteretic behavior which is specific to the few-channel regime. In the coherent limit, the amplitude of the magnetic signals is strongly enhanced due to resonance effects occurring inside the nanotube. Our calculations pave the way for experiments on low-dimensional nonlocal spin transport, which should give results remarkably different from the experiments realized so far in the multichannel diffusive incoherent regime.