250 citations · 3.9k across the 99 of their papers we have counts for
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The open XXZ-chain: Bosonisation, Bethe ansatz and logarithmic corrections
J. Sirker, M. Bortz
We calculate the bulk and boundary parts of the free energy for an open spin-1/2 XXZ-chain in the critical regime by bosonisation. We identify the cutoff independent contributions…
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…