Phonon Dispersion in hBN/Graphene Heterostructure

[Donghua-un]

Hello ALAMODE team,

I’m new to using the ALAMODE package and would appreciate your guidance.
My system consists of a heterostructure made of hBN and graphene (Gr). The interlayer interaction is modelled using the Lennard-Jones potential, while the intralayer bonded interactions are treated with the Tersoff potential.
My question is:
Is it possible to isolate the phonon dispersion of the hBN layer from the full hBN/graphene heterostructure? I am particularly interested in analysing only the hBN phonon modes and studying how the interlayer interaction with graphene affects them.
Any suggestions on how to approach this analysis using ALAMODE would be greatly appreciated.

Best regards,
ABID
Donghua university

[ttadano]

It is impossible to perfectly isolate the hBN phonon dispersion from graphene because of the interlayer interaction. Technically speaking, you can manually adjust the cutoff radius for the force constants so that the only the hBN-hBN (intralayer) force constants are computed. However, such an approach is physically inaccurate when the interlayer interaction is significant.

I would suggest that you compute the phonon of the hBN-graphen composite and then compare the projected phonon DOS of the composite and that of pure hBN.