@article{oai:oist.repo.nii.ac.jp:00002070,
 author = {Chepelianskii, A. D. and Papoular, D. and Konstantinov, D. and Bouchiat, H. and Kono, K.},
 issue = {7},
 journal = {Physical Review B},
 month = {Feb},
 note = {Electrons on the liquid helium surface form an extremely clean two-dimensional system where different plasmon excitations can coexist. Under a magnetic field, time-reversal symmetry is broken, and all the bulk magnetoplasmons become gapped at frequencies below cyclotron resonance while chiral one-dimensional edge magnetoplasmons appear at the system perimeter. We theoretically show that the presence of a homogeneous density gradient in the electron gas leads to the formation of a delocalized magnetoplasmon mode in the same frequency range as the lowest-frequency edge-magnetoplasmon mode. We experimentally confirm its existence by measuring the corresponding resonance peak in frequency dependence of the admittance of the electron gas. This allows us to realize a prototype system to investigate the coupling between a chiral one-dimensional mode and a single delocalized bulk mode. Such a model system can be important for the understanding of transport properties of topological materials where states of different dimensionality can coexist.},
 title = {Coupled pair of one- and two-dimensional magnetoplasmons on electrons on helium},
 volume = {103},
 year = {2021}
}