Evidence for three fluctuation channels in the spin resonance of the unconventional superconductor CeCoIn

非従来型超伝導体CeCoInにおける3成分により構成されるスピンレゾナンスの証明

Raymond, S.*; 金子 耕士   ; Hiess, A.*; Steffens, P.*; Lapertot, G.*

Raymond, S.*; Kaneko, Koji; Hiess, A.*; Steffens, P.*; Lapertot, G.*

Polarized inelastic neutron scattering under magnetic field is used to get a microscopic insight into the spin resonance of the heavy fermion superconductor CeCoIn. The resonance lineshape is found to depend on the neutron polarization: Some of the spectral weight is common to the two polarization channels while the remaining part is distributed equally between them. This is evidence for the spin resonance being a degenerate mode with three fluctuation channels: A Zeeman split contribution and an additional longitudinal mode.