Mahmoodian is a quantum-optics theorist working on waveguide QED and photon-photon interactions: how strongly-coupled emitters in a one-dimensional photonic channel generate non-classical photon-number correlations, and how those correlated multi-photon states can be exploited. His most sensing-relevant result is the demonstration that photon-number-correlated states produced by a single emitter can be used for quantum-enhanced metrology and absorption spectroscopy, beating the shot-noise limit with a source that requires no squeezing. He also works on the fundamental limits of quantum-enhanced measurement. 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 — his work belongs to the 'fundamental light physics' arm of the search rather than the spin arm, and it addresses the question directly downstream of pT/sqrt(Hz) ensembles: given a shot-noise-limited readout, what does non-classical light buy you? Theory PI, but tightly coupled to photonics experiments.

van Loock leads theoretical quantum optics and quantum information at Mainz, with a long-standing focus on continuous-variable quantum optics: squeezed and other nonclassical Gaussian states, non-Gaussian resources such as cat and GKP states, hybrid discrete/continuous-variable encodings, and the error-correction and repeater architectures built on them. The group also works on the fundamental limits of quantum-enhanced measurement and on how nonclassical light can be used as a metrological resource. He is theory-first, with output that directly serves the experimental quantum-optics and trapped-ion groups in Mainz. Relative to the established NV-ensemble quantum-sensing playbook (DEER, nanoscale NMR, T1 relaxometry at pT/sqrt(Hz) ensemble sensitivity), the relevance is on the fundamental-light-physics axis rather than the magnetometry axis: this is where the squeezing/nonclassical-state theory sits that would let a spin-ensemble sensor beat the standard quantum limit.