The magnetic field generated Hofstadter butterfly in twisted trilayer
graphene (TTLG) is investigated using circularly polarized light (CPL) and
longitudinal light emanating from a waveguide. We show that TTLG has two
distinct chiral limits in the equilibrium state, and the central branch of the
butterfly splits into two precisely degenerate components. The Hofstadter
butterfly appears to be more discernible. We also discovered that CPL causes a
large gap opening at the central branch of the Hofstadter butterfly energy
spectrum and between the Landau levels (LLs), with a clear asymmetry
corresponding to energy E=0. We point out that for right-handed CPL, the
central band shifts downward, in stark contrast to left-handed CPL, where the
central band shifts upward. Finally, we investigated the effect of
longitudinally polarized light, which originates from a waveguide.
Interestingly, we observed that the chiral symmetries of the Hofstadter
butterfly energy spectrum are broken for small driving strengths and get
restored at large ones, contrary to what was observed in twisted bilayer
graphene (TBLG).Comment: 10 pages, 5 figures, two-colum