Submillihertz magnetic spectroscopy performed with a nanoscale quantum sensor

• DOI: 10.1126/science.aam5532
• Publication Date: 2017-05-25T21:40:11Z
• Authors: Simon Schmitt; Tuvia Gefen; Felix M. Stürner; Thomas Unden; Gerhard Wolff; Christoph Müller; Jochen Scheuer; Boris Naydenov; Matthew Markham; Sebastien Pezzagna; Jan Meijer; Ilai Schwarz; Martin Plenio; Alex Retzker; Liam P. McGuinness; Fedor Jelezko
• Keywords: Laser linewidth; Quantum Metrology; Coherence time; Quantum sensor

Precise timekeeping is critical to metrology, forming the basis by which standards of time, length, and fundamental constants are determined. Stable clocks particularly valuable in spectroscopy because they define ultimate frequency precision that can be reached. In quantum qubit coherence time defines clock stability, from spectral linewidth We demonstrate a sensing protocol goes beyond sensor limited stability classical clock. Using this technique, we observed estimation scaling T as T-3/2 for oscillating fields. The narrow magnetometer based on single spins diamond used sense nanoscale magnetic fields with an intrinsic resolution 607 microhertz, eight orders magnitude narrower than time.