Exact Spin Dynamics of Inhomogeneous 1-d Systems at High Temperature.

ERNESTO P. DANIELI; H. M. PASTAWSKI; P. R. LEVSTEIN

PHYSICA B - CONDENSED MATTER

Elsevier

Año: 2002 vol. 320 p. 351 - 353

0921-4526

Exact Spin Dynamics of Inhomogeneous 1-d Systems at High Temperature. E. P. Danieli, H. M. Pastawski 1 , P. R. Levstein. Physica B 320/1-4 pp. 351-353.(2002)AbstractThe evaluation of spin excitation dynamics in finite 1-d systems of spins 1/2 with XY exchange interaction J acquired new interest because NMR experiments at high temperature (kBTbJ) confirmed the predicted spin wave behavior of mesoscopic echoes. In this work, we use the Jordan–Wigner transformation to obtain the exact dynamics of inhomogeneous chains and rings where the evolution is reduced to one-body dynamics. For higher dimensions, the spin excitations manifest many-body effects that can be interpreted as a simple dynamics of non-interacting fermions plus a decoherent process. r 2002 Elsevier Science B.V. All rights reserved.