"Quantum sensing with group-IV color centers in diamond: from optical antennas to reconfigurable spins" with Zixi Li, PhD candidate at the University of Chicago
Abstract: Atom-like defects in solids are promising building blocks for quantum technologies, combining the controllability of isolated quantum systems with the versatility of a solid-state platform. Among these, group-IV color centers in diamond are especially attractive because their inversion symmetry supports excellent optical coherence, while their electronic and spin properties remain highly tunable through the local solid state environment. In this talk, I will discuss two directions in which these defects can be harnessed as new kinds of quantum sensors. First, I will show that a resonantly driven germanium-vacancy center can function as an atomic optical antenna, generating a strongly enhanced local optical field that enables the sensing and control of nearby charge defects. Second, I will describe ongoing work showing that large strain can reshape the spin-orbital structure of group-IV centers, partially release the electron spin from its usual locking to the defect axis and allow its quantization axis to be modified by an external magnetic field, which provides a route to accessing and detecting a broader set of surrounding nuclear spins. Together, these results illustrate how group-IV color centers can be developed into novel quantum sensors in diamond from both optical and spin perspectives.
