Superconductivuty versus Tunneling in a Doped Antiferromagnetic Ladder
arXiv:cond-mat/9903251 · doi:10.1103/PhysRevB.60.1303
Abstract
The low-energy charge excitations of a doped antiferromagnetic ladder are modeled by a system of interacting spinless fermions that live on the same ladder. A relatively large spin gap is assumed to ``freeze out'' all spin fluctuations. We find that the formation of rung hole pairs coincides with the opening of a single-particle gap for charge excitations along chains and with the absence of coherent tunneling in between chains. We also find that such hole pairs condense into either a crystalline or superconducting state as a function of the binding energy.
15 pgs. in PLAIN TeX, 2 figs. in postscript, to appear in Phys. Rev. B