We report an electronic magnetization measurement of a quantum point contact (QPC) based on nuclear magnetic resonance (NMR) spectroscopy. We find that NMR signals can be detected by measuring the QPC conductance under in-plane magnetic fields. This makes it possible to measure, from Knight shifts of the NMR spectra, the electronic magnetization of a QPC containing only a few electron spins. The magnetization changes smoothly with the QPC potential barrier height and peaks at the conductance plateau of 0.5 ×2e2/h. The observed features are well captured by a model calculation assuming a smooth potential barrier, supporting a no bound state origin of the 0.7 structure.
@article{arxiv.1506.05477,
title = {Electronic magnetization of a quantum point contact measured by nuclear magnetic resonance},
author = {Minoru Kawamura and Keiji Ono and Peter Stano and Kimitoshi Kono and Tomosuke Aono},
journal= {arXiv preprint arXiv:1506.05477},
year = {2015}
}
Comments
5 pages main text + 6 pages supplementary material. Accepted for publication in Phys. Rev. Lett