Heat capacity of Schottky type in low-dimensional spin system

TL;DR

This paper investigates the heat capacity behavior of low-dimensional spin systems, confirming that a simplified two-level model accurately captures key features like the energy gap and transition temperature.

Contribution

It demonstrates that the two-level-system model effectively describes the heat capacity and energy gap behavior in low-dimensional spin systems, validated by numerical methods.

Findings

The two-level-system model matches the low-temperature Lanczos results.

The behavior of $T_{M}$ and the energy gap are consistent across models.

Results suggest general applicability to gapped systems.

Abstract

The heat capacity of low-dimensional spin systems is studied using theoretical and numerical techniques. Keeping only two energy states, the system is mapped onto the two -level-system (TLS) model. Using the low temperature Lanczos method, it is confirmed that the behavior of $T_{M}$ and the energy gap as functions of the control parameter is the same in the two models studied; a conclusion that can probably be extrapolated to the general case of any system that possesses an energy gap.