QDev Seminar: Leonid Abdurakhimov
Microelectronics group, Cavendish Laboratory, University of Cambridge
Strong Coupling Between Hybrid Nuclear-Electron Magnons and Microwave Photons
Recently, there has been growing interest in studies of strong coupling between spin systems and microwave photons due to its possible application in quantum information processing. Although considerable research has concentrated on strong coupling with electron spin ensembles, rather less attention has been paid to investigations of possibility of strong light-matter interaction in nuclear spin systems. In antiferromagnetic MnCO3 system, a low-frequency collective spin excitation (magnon) is the hybridized oscillation of nuclear and electron spins coupled via hyperfine interaction. By using a 3D split-ring resonator, we performed microwave spectroscopy measurements of MnCO3 system and observed strong coupling between hybridized nuclear-electron magnons and microwave photons . We also carried out time-domain studies of MnCO3 system in the regime of strong coupling, and observed Rabi-like oscillations in free induction decay (FID) signal with the oscillation period corresponding to the coupling rate of about 1 MHz. By performing spin echo measurements, we found T2 time of hybridized magnons to be about 5 µs at the temperature of 300 mK. The results reveal a new class of spin systems, in which strong coupling between nuclear spins and photons is mediated by electron spins via hyperfine interaction.
 L.V. Abdurakhimov, Yu.M. Bunkov, D. Konstantinov, PRL 114, 226402 (2015)