Direct determination of the edge-state Fermi energy in monolayer WTe2

Determine experimentally the Fermi energy of monolayer WTe2 edge states measured relative to the Kramers point, in order to assess more precisely the validity of the semiclassical approximation for periodically deformed topological-insulator edges.

Background

The paper assesses whether its semiclassical and perturbative approximations are applicable to experimentally relevant monolayer WTe2. The relevant semiclassical condition depends on the edge-state Fermi energy, but the cited experimental work did not directly measure that energy relative to the Kramers point. The authors therefore rely on indirect energy scales and order-of-magnitude estimates, leaving direct experimental determination unresolved.