Unconventional cyclotron resonance in Sr2RuO4

An angle-dependent study of the magneto-optical response of the p-wave trip let-paired perovskite superconductor Sr2RuO4\ reveals several new cyclotron resonance effects. We observe an odd-harmonic cyclotron resonance series, probably arising from the gamma Fermi surface, with a fundamental cyclotron mass of 12.6 m(e). In addition, we find several resonance branches which b ehave in unconventional ways owing to the unusual nature of the band disper sion in this material. The results confirm the complexity of the Sr2RuO4 Fe rmi surface topology and show that earlier conclusions drawn from millimetr e-wave experiments should be reconsidered. (C) 2001 Elsevier Science B.V. A ll rights reserved.