Zeptosecond‐Scale Single‐Photon Gyroscope

• DOI: 10.1002/qute.202400166
• Publication Date: 2024-07-09T02:08:16Z
• Authors: Fabrizio Sgobba; Danilo Triggiani; Vincenzo Tamma; Paolo De Natale; Gianluca Gagliardi; Saverio Avino; Luigi Santamaria ...
• Keywords: Quantum Physics; FOS: Physical sciences; Quantum Physics (quant-ph)

This paper presents an all-fiber telecom-range optical gyroscope employing a spontaneous parametric down conversion crystal to produce ultra-low intensity thermal light by tracing-out one of the heralded photons. The prototype exhibits detection limit on photon delay measurements $249$ zs over $72$ s averaging time and 26 in differential at $t=10^4$ averaging. scheme proves be most resource-efficient possible, saturating $>99.5\%$ Cram\'er-Rao bound. These results are groundbreaking context low-photon regime quantum metrology, paving way novel experimental configurations bridge optics with special or general relativity.