Hyperfine spectroscopy in a quantum-limited spectrometer [article]

S. Probst, G.L. Zhang, M. Rančić, V. Ranjan, M. Le Dantec, Z. Zhong, B. Albanese, A. Doll, R.B. Liu, J.J.L. Morton, T. Chanelière, P. Goldner (+3 others)
2021 arXiv   pre-print
We report measurements of electron spin echo envelope modulation (ESEEM) performed at millikelvin temperatures in a custom-built high-sensitivity spectrometer based on superconducting micro-resonators. The high quality factor and small mode volume (down to 0.2pL) of the resonator allow to probe a small number of spins, down to 5· 10^2. We measure 2-pulse ESEEM on two systems: erbium ions coupled to ^183W nuclei in a natural-abundance CaWO_4 crystal, and bismuth donors coupled to residual ^29Si
more » ... uclei in a silicon substrate that was isotopically enriched in the ^28Si isotope. We also measure 3- and 5-pulse ESEEM for the bismuth donors in silicon. Quantitative agreement is obtained for both the hyperfine coupling strength of proximal nuclei, and the nuclear spin concentration.
arXiv:2001.04854v3 fatcat:wttvyu73wzbfjhkqfb7jy56pma