Fig. 3: Graphite substrate controls the AB/BA contrast in t-hBN.
From: Nanoscale lattice dynamics in hexagonal boron nitride moiré superlattices
Uppercase notation (e.g., AB, BA, etc.) is reserved for hBN–hBN stacking configurations, whereas the lower case is utilized to describe various hBN stacking options on graphite (e.g., aa, ba, etc.). a Schematic of hBN/graphite stacking configurations. b Stacking energy landscapes for all three commensurate hBN/graphene configurations. Dashed black horizontal lines highlight the subtle energetic preference of AB over BA stackings. c Plot of the calculated BA–AB energy difference and d TO frequency shift for each commensurate hBN–graphene stacking. e Data points reproduce the spectrum of SBA/SAB in Fig. 2c (with the same error bars) plotted using a normalized frequency horizontal axis. Solid line: spectrum of the scattering amplitude calculated with the lightning-rod model. f Similar to e, data points reproduce the spectrum of ϕBA–ϕAB from Fig. 2f. For consistency with Fig. 2, the solid line uses the same oscillator strength and damping (not obtainable in this model) extracted from the Fig. 2i AB fitting parameters.
