Interpolation between low and high temperatures of the specific heat for spin systems

Autor(en): Schmidt, Heinz-Juergen
Hauser, Andreas
Lohmann, Andre
Richter, Johannes
Stichwörter: EXACT-DIAGONALIZATION; EXPANSION; HEISENBERG-ANTIFERROMAGNET; KAGOME LATTICE; MODEL; Physics; Physics, Fluids & Plasmas; Physics, Mathematical; RENORMALIZATION-GROUP; STATE
Erscheinungsdatum: 2017
Herausgeber: AMER PHYSICAL SOC
Journal: PHYSICAL REVIEW E
Volumen: 95
Ausgabe: 4
Zusammenfassung: 
The high temperature expansion (HTE) of the specific heat of a spin system fails at low temperatures, even if it is combined with a Pade approximation. On the other hand, we often have information about the low-temperature asymptotics (LTA) of the system. Interpolation methods combine both kind of information, HTE and LTA, in order to obtain an approximation of the specific heat that holds for the whole temperature range. Here we revisit the entropy method that has been previously published and propose two variants that better cope with problems of the entropy method for gapped systems. We compare all three methods applied to the antiferromagnetic Haldane spin-one chain and especially apply the second variant, called log Z method, to the cuboctahedron for different spin quantum numbers. In particular, we demonstrate that the interpolation method is able to detect an extra low-temperature maximum in the specific heat that may appear if a separation of two energy scales is present in the considered system. Finally, we illustrate how interpolation also works for classical spin systems.
ISSN: 24700045
DOI: 10.1103/PhysRevE.95.042110

Show full item record

Google ScholarTM

Check

Altmetric