Nanoscale spin detection of copper ions using double electron-electron resonance at room temperature

Abstract

We report the nanoscale spin detection and electron paramagnetic resonance (EPR) spectrum of copper (Cu${}^{2+}$) ions via double electron-electron resonance with single spins in diamond at room temperature and low magnetic fields. We measure unexpectedly narrow EPR resonances with linewidths $\sim 2-3$ MHz from copper-chloride molecules dissolved in poly-lysine. We also observe coherent Rabi oscillations and hyperfine splitting from single Cu${}^{2+}$ ions, which could be used for dynamic nuclear spin polarization and higher sensitivity of spin detection. We interpret and analyze these observations using both spin hamiltonian modeling of the copper-chloride molecules and numerical simulations of the predicted DEER response, and obtain a sensing volume $\sim (250\text{nm}{)}^3$. This work will open the door for copper-labeled EPR measurements under ambient conditions in bio-molecules and nano-materials.

28 pages, 9 figures, revised ms

References in corpus (3)

• High-sensitivity diamond magnetometer with nanoscale resolution
• Single DNA Electron Spin Resonance Spectroscopy in Aqueous Solutions
• Understanding the Linewidth of the ESR Spectrum Detected by a Single NV Center in Diamond

Cited by in corpus (4)

• High Frequency Magnetometry with an Ensemble of Spin Qubits in Hexagonal Boron Nitride
• Enhancement of quantum coherence in solid-state qubits via interface engineering
• Quantum spin probe of single charge dynamics
• Engineering diamond interfaces free of dark spins