Wave function for composite odd-frequency superconductors.

Berezinskii proposed a new class of superconducting state that has an anomalous gap function that is odd function of frequency.$^{1}$ Following initial work of Berezinskii there has been growing interest in properties of such superconductors.$^{2-3 }$We propose a BCS-like wave function for an s-wave triplet odd-frequency superconductor. The wave function describes a condensate of spin-0 Cooper pair and spin-1 magnon; a composite order. By minimizing a Hamiltonian, suggested earlier in Ref. [3] to study the odd-frequency superconductor, we derive the quasiparticle dispersions, the self-consistent gap equation, and the density of states. We show that the quasiparticle excitations are gapless and the superconducting transition requires a critical coupling. References: \begin{enumerate} \item V. L. Berezinskii, JETP Lett. \textbf{20, }287 (1974). \item A. Balatsky, and E. Abrahams, PRB \textbf{45}, 13125 (1992). \item E. Abrahams, A. Balatsky, D. J. Scalapino and J. R. Schrieffer, PRB \textbf{52}, 1271(1995). \end{enumerate}