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

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 نشر من قبل Poilblanc D.
 تاريخ النشر 2000
  مجال البحث فيزياء
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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.



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