On the Non-Local Surface Plasmons’ Contribution to the Casimir Force between Graphene Sheets

Herein we demonstrate the dramatic effect of non-locality on the plasmons which contribute to the Casimir forces, with a graphene sandwich as a case study. The simplicity of this system allowed us to trace each contribution independently, as we observed that interband processes, although dominating the forces at short separations, are poorly accounted for in the framework of the Dirac cone approximation alone, and should be supplemented with other descriptions for energies higher than 2.5 eV. Finally, we proved that distances smaller than 200 nm, despite being extremely relevant to state-of-the-art measurements and nanotechnology applications, are inaccessible with closed-form response function calculations at present.

The effects of Rashba spin–orbit coupling and Holstein phonons on thermodynamic properties of BN-doped graphene

Starting from the Holstein model, we have investigated the effects of Rashba spin–orbit coupling (RSOC) on density of states (DOS), electronic heat capacity (EHC) and magnetic susceptibility (MS) of boron nitride-doped (BN-doped) graphene beyond the Dirac cone approximation within the Green’s function approach. By using the self-consistent perturbation theory, retarded self-energy can be calculated. We have found that the band gap (the peak of EHC and MS) of the system increases (decreases) with RSOC and electron–phonon (e–ph) interaction. Also, the Schottky anomaly moves only to the higher temperatures for strong RSOCs and e–ph interactions. Also, our results show that the response of the system to an external magnetic field is scaled down in the presence of RSOC and e–ph interaction.