title: Superconductivity of composite particles in a two-channel Kondo lattice.
abstract: Emergence of odd-frequency s-wave superconductivity is demonstrated in the two-channel Kondo lattice by means of the dynamical mean-field theory combined with the continuous-time quantum Monte Carlo method. Around half filling of the conduction bands, divergence of an odd-frequency pairing susceptibility is found, which signals instability toward the superconductivity. The corresponding order parameter is equivalent to a staggered composite-pair amplitude with even frequencies, which involves both localized spins and conduction electrons. A model wave function is constructed for the composite order with the use of symmetry operations such as charge conjugation and channel rotations. Given a certain asymmetry of the conduction bands, another s-wave superconductivity is found that has a uniform order parameter. The Kondo effect in the presence of two channels is essential for both types of unconventional superconductivity.
authors.affiliation: Department of Basic Science, The University of Tokyo, Meguro, Tokyo 153-8902, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Hoshino
authors.affiliation: Department of Physics, Tohoku University, Sendai, Miyagi 980-8578, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kuramoto