NanoARPES of twisted bilayer graphene on SiC: absence of velocity renormalization for small angles.
The structural and electronic properties of twisted bilayer graphene (TBG) on SiC(000) grown by Si flux-assisted molecular beam epitaxy were investigated using scanning tunneling microscopy (STM) and angle-resolved photoelectron spectroscopy with nanometric spatial resolution. STM images revealed a wide distribution of twist angles between the two graphene layers. The electronic structure recorded in single TBG grains showed two closely-spaced Dirac π bands associated to the two stacked layers with respective twist angles in the range 1-3°. The renormalization of velocity predicted in previous theoretical calculations for small twist angles was not observed.
I.E.M.N., UMR CNRS 8520, Av. Poincaré CS 60069, 59652, Villeneuve d'Ascq Cedex, France.
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I
Razado-Colambo
Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin-BP 48, 91192 Gif sur Yvette Cedex, France.
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J
Avila
I.E.M.N., UMR CNRS 8520, Av. Poincaré CS 60069, 59652, Villeneuve d'Ascq Cedex, France.
J-P
JP
Nys
Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin-BP 48, 91192 Gif sur Yvette Cedex, France.
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C
Chen
I.E.M.N., UMR CNRS 8520, Av. Poincaré CS 60069, 59652, Villeneuve d'Ascq Cedex, France.
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Wallart
Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin-BP 48, 91192 Gif sur Yvette Cedex, France.
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MC
Asensio
I.E.M.N., UMR CNRS 8520, Av. Poincaré CS 60069, 59652, Villeneuve d'Ascq Cedex, France.
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Vignaud