Observation of Chirality Transfer in Twisted Few-Layer Graphene.

ABSTRACT

Chiral materials are the focus of research in a variety of fields such as chiroptical sensing, biosensing, catalysis, and spintronics. Twisted two-dimensional (2D) materials are rapidly developing into a class of atomically thin chiral materials that can be effectively modulated through interlayer twist. However, chirality transfer in chiral 2D materials has not been reported. Here, we show that the chirality from the twist interface of graphene can directly transfer to achiral few-layer graphene and lead to a strong chiroptical response probed with circularly polarized Raman spectroscopy. Distinct Raman optical activity (ROA) for the interlayer shear modes in achiral few-layer graphene is observed, with the degree of polarization reaching as high as 0.5. These findings demonstrate the programmability of chiroptical response through stacking and twist engineering in 2D materials and offer insights into the transfer of chirality in atomically thin chiral materials for optical and electronic applications.