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

The description of the numerical method of simulation based on the quantum transfer-matrix (QTM) approach is presented for diluted spin S = 1/2 chains. Modification of the extrapolation technique has been used to obtain better accuracy of numerical results. The simulations have been performed using the S = 1/2 antiferromagnetic Heisenberg model with the transverse staggered field and a uniform magnetic field perpendicular to the staggered field applicable for the diluted compound (Yb1-xLux)(4)As-3. In the model calculations the fixed microscopic parameters established earlier for the pure system have been assumed and the random impurity distribution has been considered. The experimental field-dependent specific heat of the polydomain diluted (Yb1-xLux)(4)As-3 sample is compared with that calculated using the HPC resources and providing additional verification of both the QTM method and the physical model.