Quantum sensing of magnetic fields with molecular color centers

Abstract

Molecular color centers, such as $S=1$ Cr($o$-tolyl)${}_4$, show promise as an adaptable platform for magnetic quantum sensing. Their intrinsically small size, i.e., 1-2 nm, enables them to sense fields at short distances and in various geometries. This feature, in conjunction with tunable optical read-out of spin information, offers the potential for molecular color centers to be a paradigm shifting materials class beyond diamond-NV centers by accessing a distance scale opaque to NVs. This capability could, for example, address ambiguity in the reported magnetic fields arising from two-dimensional magnets by allowing for a single sensing technique to be used over a wider range of distances. Yet, so far, these abilities have only been hypothesized with theoretical validation absent. We show through simulation that Cr($o$-tolyl)${}_4$ can spatially resolve proximity-exchange versus direct magnetic field effects from monolayer CrI${}_3$ by quantifying how these interactions impact the excited states of the molecule. At short distances, proximity exchange dominates through molecule-substrate interactions, but at further distances the molecule behaves as a typical magnetic sensor, with magnetostatic effects dominating changes to the energy of the excited state. Our models effectively demonstrate how a molecular color center could be used to measure the magnetic field of a 2D magnet and the role different distance-dependent interactions contribute to the measured field.

7 pages, 4 figures

References in corpus (7)

• High-sensitivity diamond magnetometer with nanoscale resolution
• Magnetic 2D materials and heterostructures
• Probing magnetism in 2D materials at the nanoscale with single spin microscopy
• Magnetic order in $\alpha$-RuCl${}_3$: a honeycomb lattice quantum magnet with strong spin-orbit coupling
• Delta Self-Consistent Field as a method to obtain potential energy surfaces of excited molecules on surfaces
• Resonant optical spectroscopy and coherent control of Cr4+ spin ensembles in SiC and GaN
• Giant proximity exchange and valley splitting in transition metal dichalcogenide/$h\mathrm{BN}$/(Co, Ni) heterostructures

Cited by in corpus (6)

• Room-temperature optically detected coherent control of molecular spins
• Alternant Hydrocarbon Diradicals as Optically Addressable Molecular Qubits
• Quantum Sensing of Magnetic Fields with Molecular Spins
• Low temperature decoherence dynamics in molecular spin systems using the Lindblad master equation
• Isofrequency spin-wave imaging using color center magnetometry for magnon spintronics
• Numerically exact quantum dynamics with tensor networks: Predicting the decoherence of interacting spin systems