Artículos de revistas
Quantum-Critical Spin Dynamics in Quasi-One-Dimensional Antiferromagnets
Fecha
2012Registro en:
PHYSICAL REVIEW LETTERS, COLLEGE PK, v. 109, n. 17, supl. 1, Part 1, pp. 4051-4058, OCT 26, 2012
0031-9007
10.1103/PhysRevLett.109.177206
Autor
Mukhopadhyay, S.
Klanjsek, M.
Grbic, M. S.
Blinder, R.
Mayaffre, H.
Berthier, C.
Horvatic, M.
Continentino, M. A.
Paduan Filho, Armando
Chiari, B.
Piovesana, O.
Institución
Resumen
By means of nuclear spin-lattice relaxation rate T-1(-1), we follow the spin dynamics as a function of the applied magnetic field in two gapped quasi-one-dimensional quantum antiferromagnets: the anisotropic spin-chain system NiCl2-4SC(NH2)(2) and the spin-ladder system (C5H12N)(2)CuBr4. In both systems, spin excitations are confirmed to evolve from magnons in the gapped state to spinons in the gapless Tomonaga-Luttinger-liquid state. In between, T-1(-1) exhibits a pronounced, continuous variation, which is shown to scale in accordance with quantum criticality. We extract the critical exponent for T-1(-1), compare it to the theory, and show that this behavior is identical in both studied systems, thus demonstrating the universality of quantum-critical behavior.