R. Matysiak

Simulations of the low-dimensional magnetic systems by the quantum transfer-matrix technique

Abstract A numerical quantum transfer-matrix approach based on the Suzuki–Trotter formula and the checker-board decomposition is presented in the framework of quantum statistical mechanics. It is applied to the supramolecular cluster Mn6 (i.e. [Mn(hfac)2NITPh]6) and to a number of the macroscopic quasi-one-dimensional magnets. The latter include: (i) the macroscopic Haldane-gap spin S=1 chains and molecular-based magnetic spin S=1 chains (with uniform and alternating interaction couplings); (ii) the spin-Peierls CuGeO3 and Pb[Cu(SO4)(OH)2] compounds subject to frustration; (iii) Yb4As3 which is a new semimetallic material being the first example of the antiferromagnetic S=1/2 spin chain with the induced staggered field appearing as a result of the antisymmetric Dzyaloshinsky–Moriya interaction. The compounds in question can be characterized within the spin Heisenberg models and their thermodynamic properties at finite temperatures are calculated using our own codes. Our simulation results are compared with the available experimental results and a quantitative agreement has been established. The large-scale numerical simulations were carried out on the Cray and Silicon Graphics supercomputers, using the parallelized and vectorized codes, exploiting the Parallel Virtual Machine (PVM) and the Message Passing Interface (MPI) system libraries.

Specific heat of segmented Heisenberg quantum spin chains in (Yb1-xLux)4As3

We report low-temperature specific heat,

Application of Parallel Computing in the Transfer-Matrix Simulations of the Supramolecular Rings

C(T)

Large-scale simulations of the finite-temperature properties of the molecular assemblies Mn6 and Ni12

, measurements on (Yb

Deterministic Large-Scale Simulations of the Low-Dimensional Magnetic Spin Systems

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Application of Parallel Computing in the Transfer - Matrix Simulations of the Supramolecules Mn6 and Ni12

Lu

Application of Numerical Quantum Transfer-Matrix Approach in the Randomly Diluted Quantum Spin Chains

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Bose glass behavior in (Yb

)

_{1-x}

_4

Lu

As