[19a-E208-1~10] 【CS.3】 Code-sharing Session of 3.10 & 3.11 & 9.2 & 11.5 & 13.6

[19a-E208-7] Electron spin resonance spectroscopy with sensitivity of 20 spins/√Hz using a superconducting flux qubit

Rangga P. Budoyo¹, Kosuke Kakuyanagi¹, 〇Hiraku Toida¹, Yuichiro Matsuzaki¹, Shiro Saito¹ (1.NTT BRL)

Keywords:superconductor, qubit, electron spin resonance

We perform electron spin resonance spectroscopy using a superconducting flux qubit. The flux qubit is used as a magnetometer in this experiment. The sensitivity of the spectrometer is improved to 20 spins/√Hz by reading out the flux qubit with a Josephson bifurcation amplifier. We also improve the sensing volume to 6 fL by shrinking the loop size of the flux qubit. These values are 20 times (sensitivity) and 8 times (sensing volume) better than our previous experiment.