Develops computational methods (DFT + many-body perturbation theory, quantum embedding) to predict properties of spin defects for quantum sensing and computing. Directions: (1) first-principles prediction of coherence properties, zero-phonon lines, and spin-photon coupling for NV, SiC divacancy, Er, and other color center platforms; (2) high-throughput screening of novel spin defect candidates in 2D materials and oxides; (3) quantum embedding methods for strongly correlated defects. Director MICCoM; NAS member; Argonne senior scientist.

Kuncic works across medical physics and nanoscale systems: nanoparticle-enhanced radiotherapy and dosimetry (where high-Z nanoparticles act as local dose amplifiers and the physics question is energy deposition at nanometre scales), nanoparticle contrast agents and theranostics, and — separately — neuromorphic nanowire networks as physical computing substrates. The medical-physics thread is the relevant one here: it is about quantifying and imaging what a nanoscale probe does inside tissue. Positioned against the established body of NV-ensemble quantum sensing work — DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity — the nanoparticle-in-tissue problem she works on is the same delivery-and-quantification problem that determines whether an in-cell nanodiamond sensor operating near the pT/sqrt(Hz) regime reports anything biologically meaningful. Borderline inclusion; a candidate would be bringing quantum sensing to her, not the reverse.

Main works on nonlinear dynamics, semiclassics and quantum chaos, and is the principal theorist behind Stuttgart's Rydberg-exciton programme: high-n excitons in cuprous oxide, where the giant excitonic Rydberg states show magnetoexciton spectra, level statistics and symmetry breaking that his group models quantitatively. This is the theoretical partner to Giessen's (existing PI) experimental Rydberg-exciton work. Relative to the established NV-ensemble quantum-sensing playbook (DEER, nanoscale NMR, T1 relaxometry at pT/sqrt(Hz) ensemble sensitivity), a borderline theory inclusion, kept because Rydberg excitons are a genuinely promising solid-state electrometry platform -- giant polarizability in a semiconductor rather than a vapour cell -- and this is the group that understands their spectra.

Rahman does large-scale atomistic modelling of semiconductor quantum devices: tight-binding and DFT calculations of donor and quantum-dot wavefunctions, valley physics, spin-orbit coupling, hyperfine interactions and the response of all of these to strain and electric field, at system sizes large enough to represent a real device. The group works hand-in-glove with the Morello, Dzurak, Simmons and Rogge experiments, and increasingly uses machine learning to invert measurements into structural information. Positioned against the established body of NV-ensemble quantum sensing work — DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity — the same first-principles machinery is what predicts the hyperfine and spin-bath environment that determines T2 — and therefore the achievable pT/sqrt(Hz) sensitivity — of any solid-state spin sensor, including NV. Computational PI; would suit a candidate wanting a theory/experiment bridge role.