Inductive-detection electron-spin resonance spectroscopy with 65 spins/Hz sensitivity
Inductive-detection electron-spin resonance spectroscopy with 65 spins/Hz sensitivity
We report electron spin resonance spectroscopy measurements performed at millikelvin temperatures in a custom-built spectrometer comprising a superconducting micro-resonator at $7$ GHz and a Josephson parametric amplifier. Owing to the small ${\sim}10^{-12}\lambda^3$ magnetic resonator mode volume and to the low noise of the parametric amplifier, the spectrometer sensitivity reaches $260\pm40$ …