Two-band model of T-graphene

Utilizing a two-band tight-binding Hamiltonian model in conjunction with Green’s function methodology, this study examines the effects of localized \(\sigma\) and delocalized \(\pi\) electrons on the density of states, Pauli paramagnetic susceptibility, and electronic heat capacity of a T-graphene sheet. The analysis reveals an expansion in the bandwidth and an increase in the number of Van-Hove singularities. Importantly, in addition to the magnetic characteristics, which encompass diamagnetism in graphene-based nanosystems, a paramagnetic response linked to the itinerant \(\pi\) electrons can also manifest. Furthermore, a Schottky anomaly in the heat capacity has been observed at various temperatures, attributed to the contributions from the \(\sigma\) and \(\pi\) bands. This investigation underscores the significant contributions of both \(\sigma\) and \(\pi\) electrons to the aforementioned physical properties.