Hahn echo and criticality in spin-chain systems
School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian, 116024, P.R. China
Corresponding author: a email@example.com
Published online: 19 September 2007
We present a theory to establish a relation between Hahn spin-echo of a spin-1/2 particle and quantum phase transitions in many-body systems. The Hahn echo is calculated and discussed at zero as well as at finite temperatures. On the example of XY model, we show that the critical points of the chain are marked by the extremal values in the Hahn echo, and can influence the Hahn echo in finite temperatures. An explanation for the relation between the echo and criticality is also presented.
PACS: 03.65.Ud – Entanglement and quantum nonlocality / 05.70.Jk – Critical point phenomena
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2007