Sensing at the Quantum Speed Limit

In this presentation, we explore advancements in time-resolved quantum sensing, combining both theoretical and experimental insights. Quantum sensors, particularly those based on spin defects in solids like nitrogen-vacancy (NV) centers in diamond, are traditionally optimized for sensitivity and precision in detecting static or narrow-band dynamical signals. However, the best possible time resolution is limited by the quantum speed limit (QSL) – the minimum time required to transition between quantum states. We demonstrate that a bipartite control sequence involving phase-shifted pulses can reach this QSL, providing a pathway to optimal temporal performance. Experimentally, we demonstrate sensing with a time resolution down to 1 ns. These advances position table-top NV quantum magnetometers as competitive with large-facility synchrotron X-ray techniques for time-resolved studies and highlight their growing role in spintronics, mesoscopic physics, and nanoscale device metrology.