Abstract
Quantum interference is studied in a three-band model of pseudospin-one fermions in the α-T₃ lattice. We derive a general formula for magnetoconductivity that predicts a rich crossover between weak localization (WL) and weak antilocalization (WAL) in various scenarios. Recovering the known results for graphene (α=0), we remarkably discover that WAL is notably enhanced when one deviates slightly from the graphene lattice, i.e. when α>0, even though Berry's phase is no longer π. This is attributed to the presence of multiple Cooperon channels. Upon further increasing α, a crossover to WL occurs that is maximal for the case of the Dice lattice (α=1). Our work distinctly underscores the role of non-trivial band topology in the localization properties of electrons confined to the two-dimensional α-T₃ lattice.