Competition of pairing symmetries and a mechanism for Berezinskii pairing in quasi-one-dimensional systems

We revisit the pairing symmetry competition in quasi-one-dimensional systems. We show that spin-triplet s-wave pairing, where the pair is formed by electrons with different times and has an odd-frequency symmetry, can be realized in systems with one-dimensionality when the strength of charge fluctuation exceeds that of spin fluctuation. The present study provides a mechanism for this exotic pairing proposed by Berezinskii [JETP Lett. 20, 287 (1974)].