  Twisted bilayer graphene (tBLG) represents a family of unique materials with
optoelectronic properties tuned by the rotation angle between the two layers.
The presented work shows an additional way of tweaking the electronic structure
of tBLG: by modifying the interlayer distance, for example by a small uniaxial
out-of-plane compression. We have focused on the optical transition energy,
which shows a clear dependence on the interlayer distance, both experimentally
and theoretically.
