Nitrogen-vacancy (NV) centers in diamond offer a “uniquely quantum handle” for controlling mechanical systems. While NV-based sensing in bulk diamond has reached high levels of maturity —enabling applications from in vivo thermometry in biological systems and characterizing local magnetic environments in quantum materials to nanoscale EPR spectroscopy of individual surface spins— a new frontier lies in using these spins to prepare macroscopic mechanical superpositions.

In this talk, I will report on our progress toward preparing non-classical motional states of micron-scale diamonds levitated in a hybrid magneto-gravitational trap. This platform achieves exceptional environmental isolation and long-lived mechanical coherence by decoupling the particle from a physical substrate. I will describe our strategy to coherently couple the internal NV spin to the particle’s center-of-mass motion via strong magnetic field gradients, aiming to probe position-space decoherence at mesoscopic scales.

Crucially, the mechanical oscillation frequency in our trap is explicitly gravity-dependent, opening a new pathway for quantum-enhanced gravimetry. I will present recent experimental advances in trap design, spin control, and our progress toward motional state preparation. Even in the pre-ground-state cooling regime, this system provides a powerful testbed for exploring highly sensitive force sensing and motional entanglement generation.

Zoom: https://upenn.zoom.us/j/97854653721