  Van der Waals heterostructures based on two-dimensional materials have
recently become a very active topic of research in spintronics, both aiming at
a fundamental description of spin dephasing processes in nanostructures and as
a potential element in spin-based information processing schemes. Here, we
theoretically investigate the magnetoconductance of mesoscopic devices built
from graphene proximity-coupled to a high spin-orbit coupling material. Through
numerically exact tight-binding simulations, we show that the interfacial
breaking of inversion symmetry generates robust weak antilocalization even when
the $z\rightarrow -z$ symmetric spin-orbit coupling in the quantum dot
dominates over the Bychkov--Rashba interaction. Our findings are in interpreted
on the light of random matrix theory, which links the observed behavior of
quantum interference corrections to a transition from circular-orthogonal to
circular-sympletic ensemble.
