65 citations · 274 across the 9 of their papers we have counts for
10 papers
Quantum versus classical behavior in the boundary susceptibility of the ferromagnetic Heisenberg chain
J. Sirker, M. Bortz
We calculate the temperature dependence of the boundary susceptibility for the quantum ferromagnetic Heisenberg chain by a modified spin-wave theory (MSWT). We find that $χ_B…
Real-time dynamics at finite temperature by DMRG: A path-integral approach
J. Sirker, A. Klümper
We propose a path-integral variant of the DMRG method to calculate real-time correlation functions at arbitrary finite temperatures. To illustrate the method we study the longitudi…
Boundary susceptibility in the open XXZ-chain
Michael Bortz, Jesko Sirker
In the first part we calculate the boundary susceptibility in the open -chain at zero temperature and arbitrary magnetic field by Bethe ansatz. We present analytical…
Bose-Einstein condensation of magnons in TlCuCl
J. Sirker, A. Weisse, O. P. Sushkov
A quantitative study of the field-induced magnetic ordering in TlCuCl in terms of a Bose-Einstein condensation (BEC) of magnons is presented. It is shown that the hitherto prop…
Consequences of spin-orbit coupling for the Bose-Einstein condensation of magnons
J. Sirker, A. Weiße, O. P. Sushkov
In the first part we discuss how the BEC picture for magnons is modified by anisotropies induced by spin-orbit coupling. In particular we focus on the effects of antisymmetric spin…
Thermodynamics of a one-dimensional S=1/2 spin-orbital model
J. Sirker
The thermodynamic properties of a one-dimensional model describing spin dynamics in the presence of a twofold orbital degeneracy are studied numerically using the transfer-matrix r…