Field-dependent specific heat and magnetization for the S=12 antiferromagnetic chain Yb4As3: simulation and experiments

The S=12 antiferromagnetic Heisenberg model with the transverse staggered field and uniform magnetic field perpendicular to the staggered field is applied to the semimetallic compound Yb4As3. The field-dependent specific heat for infinite and finite chains as well as the magnetization for infinite chains are calculated by the numerical quantum transfer-matrix method. Specific heat data for polydomain samples of Yb4As3 and (Yb0.99Lu0.01)4As3 at B=12T are presented and compared with numerical results obtained for microscopic parameters taken from theoretical predictions. Magnetization data for single domain and polydomain samples of Yb4As3 are also compared with simulation results.