  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.
