Hyperfine spectroscopy in a quantum-limited spectrometer.

Sebastian Probst,Philippe Goldner,Daniel Esteve,Denis Vion,Vishal Ranjan,Miloš Rančić,Patrice Bertet,John Morton,Andrin Doll,Zhonghan Zhang,Thierry Chanelière,Marianne Le Dantec,Bartolo Albanese,Gengli Zhang,Ren Bao Liu

doi:10.5194/mr-1-315-2020

Abstract

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 0.2 pL) of the resonator allow us to probe a small number of spins, down to . We measure two-pulse ESEEM on two systems: erbium ions coupled to nuclei in a natural-abundance crystal and bismuth donors coupled to residual nuclei in a silicon substrate that was isotopically enriched in the isotope. We also measure three- and five-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.

Highlights

Electron paramagnetic resonance (EPR) spectroscopy provides a set of versatile tools to study the magnetic environment of unpaired electron spins (Schweiger and Jeschke, 2001)
We have reported two, three, and five-pulse electron-spin-echo envelope modulation (ESEEM) measurements using a quantum-limited EPR spectrometer on two model systems: erbium ions in a CaWO4 matrix and bismuth donors in silicon
Whereas the erbium measurements are done in a commonly used regime of high field, the bismuth donor measurements are performed in an unusual regime of low nuclear-spin density, low hyperfine coupling, and almost zero magnetic field

Summary

Introduction

Electron paramagnetic resonance (EPR) spectroscopy provides a set of versatile tools to study the magnetic environment of unpaired electron spins (Schweiger and Jeschke, 2001). EPR spectrometers rely on the inductive detection of the spin signal by a three-dimensional microwave resonator tuned to the spin Larmor frequency. Electrical (Elzerman et al, 2004; Veldhorst et al, 2014; Morello et al, 2010; Pla et al, 2012), optical (Wrachtrup et al, 1993; Jelezko et al, 2004), and scanning-probe-based (Rugar et al, 2004; Baumann et al, 2015) detection methods of magnetic resonance have reached sufficient sensitivity to detect individual electron spins.

Methods

Results

Conclusion