Evolution of the Spin Gap Upon Doping a 2-Leg Ladder

Didier Poilblanc (1) , Olivier Chiappa (1) , Jose Riera (1) , S. R. White , D. J. Scalapino

1 GPT-LPQ - Groupe de Physique Théorique (LPQ)

The evolution of the spin gap of a 2-leg ladder upon doping depends upon the nature of the lowest triplet excitations in a ladder with two holes. Here we study this evolution using various numerical techniques for a t-t'-J ladder as the next-near-neighbor hopping t' is varied. We find that depending on the value of t', the spin gap can evolve continuously or discontinuously and the lowest triplet state can correspond to a magnon, a bound magnon-hole-pair, or two separate quasi-particles. Previous experimental results on the superconducting two-leg ladder Sr12Ca2Cu24O41 are discussed.

Domaines: Autre [cond-mat.other]

Didier Poilblanc, Olivier Chiappa, Jose Riera, S. R. White, D. J. Scalapino. Evolution of the Spin Gap Upon Doping a 2-Leg Ladder. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2000, 62, pp.R14633-R14636. ⟨hal-00149126⟩