1998/12/15 by T. Antal, Z. Rácz, A. Rákos +1 · 1 citation
Physics and Astronomy · #cond-mat.stat-mech
paper · pdf · doi:10.1103/physreve.59.4912
published as Phys. Rev. E59, 4912 (1999) · RevTex, 8 pages, 3 ps figures
arxiv created 1998/12/15 · arxiv updated 2009/11/30
We study the connection between magnetization transport and magnetization profiles in zero-temperature XX chains. The time evolution of the transverse magnetization, m(x,t), is calculated using an inhomogeneous initial state that is the ground state at fixed magnetization but with m reversed from -m0 for x<0 to m0 for x>0. In the long-time limit, the magnetization evolves into a scaling form m(x,t)=P(x/t) and the profile develops a flat part (m=P=0) in the |x/t|< c(m0) region. The flat region shrinks to zero if m0->1/2 while it expands with the maximum velocity, c0=1, for m0->0. The states emerging in the scaling limit are compared to those of a homogeneous system where the same magnetization current is driven by a bulk field, and we find that the expectation values of various quantities (energy, occupation number in the fermionic representation) agree in the two systems.