@article{oai:oist.repo.nii.ac.jp:00002085,
 author = {Kawakami, Erika and Elarabi, Asem and Konstantinov, Denis},
 issue = {10},
 journal = {Physical Review Letters},
 month = {Mar},
 note = {We report the first direct observation of the decay of the excited-state population in electrons trapped on the surface of liquid helium. The relaxation dynamics, which are governed by inelastic scattering processes in the system, are probed by the real-time response of the electrons to a pulsed microwave excitation. Comparison with theoretical calculations allows us to establish the dominant mechanisms of inelastic scattering for different temperatures. The longest measured relaxation time is around 1  μs at the lowest temperature of 135 mK, which is determined by the inelastic scattering due to the spontaneous two-ripplon emission process. Furthermore, the image-charge response shortly after applying microwave radiation reveals interesting population dynamics due to the multisubband structure of the system.},
 title = {Relaxation of the Excited Rydberg States of Surface Electrons on Liquid Helium},
 volume = {126},
 year = {2021}
}