Electronic magnetization of a quantum point contact measured by nuclear magnetic resonance

Abstract

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 $\times$ $2e^2/h$. 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.

5 pages main text + 6 pages supplementary material. Accepted for publication in Phys. Rev. Lett

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Cited by in corpus (3)

• The 0.7 anomaly in quantum point contact; many-body or single-electron effect?
• Scanning Tunneling Microscopy in high vectorial magnetic fields
• Dynamical nuclear spin polarization in a quantum dot with an electron spin driven by electric dipole spin resonance