1997/06/13 by G. Chaboussant, M. -H. Julien, M.-H. Julien +8 · 5 citations
Materials Science · Physics and Astronomy · #Magnetism in coordination complexes #Organic and Molecular Conductors Research #Physics of Superconductivity and Magnetism #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.79.925
published as Phys. Rev. Lett. vol 79, 925 (1997) · 4 pages, 4 figures, to be published in Phys. Rev. Letters
arxiv created 1997/06/13 · openalex publication_date 1997/08/04 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The 1H hyperfine shift K and NMR relaxation rate T1^\ensuremath-1 have been measured as a function of temperature in the S\phantom\rule0ex0ex=\phantom\rule0ex0ex1/2 Heisenberg antiferromagnetic ladder compound Cu2(C5H12N2)2Cl4. The presence of a spin gap \ensuremathΔ\ensuremath≃J_\ensuremath⊥\ensuremath-J_\ensuremath∥ in this strongly coupled ladder ( J_\ensuremath∥<J_\ensuremath⊥) is supported by the K and T1^\ensuremath-1 results. By comparing T1^\ensuremath-1 at two different 1H sites, we infer the evolution of the spectral functions Sz(q,\ensuremathωn) and S_\ensuremath⊥(q,\ensuremathωn). When the gap is significantly reduced by the magnetic field, two different channels of nuclear relaxation, specific to gapped antiferromagnets, are identified and are in agreement with theoretical predictions.