114 citations · 440 across the 10 of their papers we have counts for
10 papers
Ground-state phases of rung-alternated spin-1/2 Heisenberg ladder
F. Amiri, G. Sun, H. -J. Mikeska +1
The ground-state phase diagram of Heisenberg spin-1/2 system on a two-leg ladder with rung alternation is studied by combining analytical approaches with numerical simulations. For…
Phase diagrams of spin ladders with ferromagnetic legs
T. Vekua, G. I. Japaridze, H. -J. Mikeska
The low-temperature properties of the spin S=1/2 ladder with anisotropic ferromagnetic legs are studied using the continuum limit bosonization approach. The weak-coupling ground st…
Perturbation theories for the S=1/2 spin ladder with four-spin ring exchange
M. Mueller, T. Vekua, H. -J. Mikeska
The isotropic S=1/2 antiferromagnetic spin ladder with additional four-spin ring exchange is studied perturbatively in the strong coupling regime with the help of cluster expansion…
Elementary excitations in one-dimensional spin-orbital models: neutral and charged solitons and their bound states
A. K. Kolezhuk, H. -J. Mikeska, U. Schollwoeck
We study, both numerically and variationally, the interplay between different types of elementary excitations in the model of a spin chain with anisotropic spin-orbit coupling, in…
On the dynamics of coupled S=1/2 antiferromagnetic zig-zag chains
M. Mueller, H. -J. Mikeska
We investigate the elementary excitations of quasi one-dimensional S=1/2 systems built up from zig-zag chains with general isotropic exchange constants, using exact (Lanczos) diago…
Nonlinear sigma model study of a frustrated spin ladder
C. -M. Nedelcu, A. K. Kolezhuk, H. -J. Mikeska
A model of two-leg spin-S ladder with two additional frustrating diagonal exchange couplings J_{D}, J_{D}' is studied within the framework of the nonlinear sigma model approach. Th…
Non-Haldane Spin Liquid Models with Exact Ground States
A. K. Kolezhuk, H. -J. Mikeska
We present a family of spin ladder models which admit exact solution for the ground state and exhibit non-Haldane spin liquid properties as predicted recently by Nersesyan and Tsve…
Elementary Excitations of Heisenberg Ferrimagnetic Spin Chains
Shoji Yamamoto, S. Brehmer, H. -J. Mikeska
We numerically investigate elementary excitations of the Heisenberg alternating-spin chains with two kinds of spins 1 and 1/2 antiferromagnetically coupled to each other. Employing…
Elementary excitations in the gapped phase of a frustrated S=1/2 spin ladder: from spinons to the Haldane triplet
S. Brehmer, A. K. Kolezhuk, H. -J. Mikeska +1
We use the variational matrix-product ansatz to study elementary excitations in the S=1/2 ladder with additional diagonal coupling, equivalent to a single S=1/2 chain with alternat…
Phase diagram and hidden order for generalized spin ladders
S. Brehmer, H. -J. Mikeska, U. Neugebauer
We investigate the phase diagram of antiferromagnetic spin ladders with additional exchange interactions on diagonal bonds by variational and numerical methods. These generalized s…