42 citations · 80 across the 7 of their papers we have counts for
6 papers · 1 filter
Exact description of the magnetoelectric effect in the spin-1/2 XXZ-chain with Dzyaloshinskii-Moriya interaction
Michael Brockmann, Andreas Klümper, Vadim Ohanyan
We consider a simple integrable model of a spin chain exhibiting the Magnetoelectric Effect (MEE). Starting from the periodic S=1/2 XXZ-chain with Dzyaloshinskii-Moriya terms, whic…
Doping a Mott insulator with orbital degrees of freedom
J. Sirker, J. Damerau, A. Klümper
We study the effects of hole doping on one-dimensional Mott insulators with orbital degrees of freedom. We describe the system in terms of a generalized t-J model. At a specific po…
Quantum phase transitions and thermodynamics of quantum antiferromagnets with competing interactions
Christian Trippe, Andreas Klümper
We study the isotropic Heisenberg chain with nearest and next-nearest neighbour interactions. The ground state phase diagram is constructed in dependence on the additonal interacti…
S=1/2 antiferromagnetic Heisenberg chain with staggered fields: Copper pyrimidine and copper benzoate using the density matrix renormalization group for transfer matrices
S. Glocke, A. Klümper, H. Rakoto +3
We consider the spin-1/2 antiferromagnetic Heisenberg chain in a staggered magnetic field describing materials such as copper benzoate and copper pyrimidine dinitrate. Using the de…
Crossover from Anderson- to Kondo-like behavior: Universality induced by spin-charge separation
Michael Bortz, Andreas Klümper, Christian Scheeren
The thermodynamics of a lattice regularized asymmetric Anderson impurity in a correlated host is obtained by an exact solution. The crossover from the Anderson- to the Kondo-regime…
Integrability of quantum chains: theory and applications to the spin-1/2 chain
Andreas Klümper
In this contribution we review the theory of integrability of quantum systems in one spatial dimension. We introduce the basic concepts such as the Yang-Baxter equation, commuting…