The tight binding approximation and thermodynamic functions

TL;DR

This paper investigates how thermodynamic functions depend on energy band occupation and temperature using the one-band tight binding approximation, highlighting differences from free electron gas behavior.

Contribution

It provides detailed calculations of various thermodynamic quantities within the tight binding model, revealing unique features due to limited energy spectrum.

Findings

Distinct behavior of thermodynamic functions compared to free electron gas

Calculated Fermi energy, density of states, and other thermodynamic quantities

Identified peculiarities arising from limited energy spectrum

Abstract

The various thermodynamic functions dependence on degree of energy band occupation and temperature was studied. The one-band tight binding approximation for the electron energy spectrum was used. The Fermi energy, density of states, degeneracy temperature, chemical potential, partition function, thermodynamic potential, energy, free energy, entropy, heat capacity, spin magnetization and initial susceptibility were calculated. The limited energetic spectrum leads to the peculiarities in the behavior of these quantities in comparison with free electron gas.