Phase-controlled coherent dynamics of a single spin under closed-contour interaction. Issue 11 (November 2018)

• Record Type: Journal Article
• Authors: Barfuss, Arne; Kölbl, Johannes; Thiel, Lucas; Teissier, Jean; Kasperczyk, Mark; Maletinsky, Patrick
• Is Part Of: Nature physics. Volume 14:Issue 11(2018)
• Page Start: 1087
• Page End: 1091
• Publication Date: 2018-11
• Subjects: Physics -- Periodicals; 530.05
• DOI: 10.1038/s41567-018-0231-8
• Languages: English
• ISSNs: 1745-2473

Abstract

Abstract In three-level quantum systems, interference between two simultaneously driven excitation pathways can give rise to effects such as coherent population trapping1, 2 and electromagnetically induced transparency3 . The possibility to exploit these effects has made three-level systems a cornerstone of quantum optics. Coherent driving of the third available transition forms a closed-contour interaction (CCI), which yields fundamentally new phenomena, including phase-controlled coherent population trapping4, 5 and phase-controlled coherent population dynamics6 . Despite attractive prospects, prevalent dephasing in experimental systems suitable for CCI driving has made its observation elusive7–10 . Here, we exploit recently developed methods for coherent manipulation of nitrogen–vacancy electronic spins to implement and study highly coherent CCI driving of a single spin. Our experiments reveal phase-controlled quantum interference, reminiscent of electron dynamics on a closed loop threaded by a magnetic flux, which we synthesize from the driving-field phase11 . Owing to the nature of the dressed states created under CCI, we achieve nearly two orders of magnitude improvement of the dephasing times, even for moderate drive strengths. CCI driving constitutes a novel approach to coherent control of few-level systems, with potential for applications in quantum sensing or quantum information processing. Coherent driving of all transitions of a three-level system generates a closed-contour interaction, which is here shown to create efficient manipulation methods for electronic spins in nitrogen–vacancy centres in diamond.