title: 63Cu NQR evidence of dimensional crossover to anisotropic 2D regime in S = 1 / 2 three-Leg ladder Sr2Cu3O5
abstract: We probed spin-spin correlations up to 725 K with 63Cu nuclear quadrupole resonance in the S = 1 / 2 three-leg ladder Sr2Cu3O5. We present experimental evidence that below 300 K weak interladder coupling causes dimensional crossover of the spin-spin correlation length xi from the quasi-1D (xi approximately 1 / T) to the anisotropic 2D regime ( xi approximately exp2pirho(s) / T, where 2pirho(s) = 290+/-30 K is the effective spin stiffness).
authors.affiliation: Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 and Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.initials: KR
authors.lastname: Thurber
authors.initials: T
authors.lastname: Imai
authors.initials: T
authors.lastname: Saitoh
authors.initials: M
authors.lastname: Azuma
authors.initials: M
authors.lastname: Takano
authors.initials: FC
authors.lastname: Chou