  We report electron transport studies in an encapsulated few-layer WTe$_2$ at
low temperatures and high magnetic fields. The magnetoconductance reveals a
temperature-induced crossover between weak antilocalization (WAL) and weak
localization (WL) in quantum diffusive regime. We show that the crossover
clearly manifests coexistence and competition among several characteristic
lengths, including the dephasing length, the spin-flip length, and the mean
free path. In addition, low temperature conductance increases logarithmically
with the increase of temperature indicating an interplay of electron-electron
interaction (EEI) and spin-orbit coupling (SOC). We demonstrate the existences
and quantify the strengths of EEI and SOC which are considered to be
responsible for gap opening in the quantum spin hall state in WTe2 at the
monolayer limit.
