Achieving Sub-Zeptonewton Force Sensitivity and Spin-Motion Entanglement in Levitated Diamond via Pulsed Backaction Evasion
Researchers developed a system coupling an NV center spin to levitated diamond motion to achieve sub-zeptonewton force sensing and robust spin-mechanical entanglement. By using Carr-Purcell sequences, they suppressed backaction noise, reaching sensitivities below 10^-23 N/$ ext{ extbar}$Hz at 104 Hz. This demonstrates a practical path for using levitated nanodiamonds as high-precision quantum sensors.