Toward Sharp-Resolution Thermal Sensitivity in 59Co Nuclear-Spin Qubits

Researchers from The Ohio State University are studying how metal-ion nuclear spin qubits sense and respond to changes in local thermal conditions. Understanding thermal sensitivity of spin systems is key to understanding functionality in devices and in vivo for bioimaging applications. Key literature demonstrations show that sensitivities can be very large for nuclear spins, which hold key advantages over electron spin counterparts, but the molecular handles to fine tune that sensitivity are poorly defined. The research team involved in this proposal will use molecular inorganic chemistry to test key mechanistic hypotheses for controlling thermal sensitivity of nuclear spins. In the long term, this work will develop new types of ultra-sensitive spin qubits for quantum information science applicable in both information processing and biosensing applications. Alongside the efforts at the bench, the participating research team will be heavily involved in quantum teaching and outreach efforts through the QuSTEAM nonprofit. The specific experimentation of the project will investigate several key aspects of thermal sensitivity. Experiments predominantly start with molecular synthesis to test hypotheses regarding the influence of composition/structure, then test the impacts on the spin via solution-phase and solid-state NMR spectroscopic measurements. The general class of molecules that are a part of these studies are metal complexes: a central metal ion contains a magnetic nucleus that serves as the nuclear spin qubit, and this ion is surrounded by a designed set of ligands (organic matter) that controls the metals properties. Specific hypotheses of this project focus on the use of electron-spin effects to control nuclear spin properties; how molecular structure influences NMR linewidths; and whether relatively unexplored and exotic nuclei enable substantial gains in thermal sensing resolution. The work will use cutting-edge equipment: the highest-field-commercial NMR spectrometer in the USA for Cobalt-59 studies at The Ohio State University and, separately, world-leading magnetic resonance facilities at the National High Magnetic Field Laboratory. Connections between the outcomes of these measurements and the physical/electronic structures of measured complexes will provide the desired scientific insights of the work. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.