▎ 摘　　要

We theoretically construct an experimental observable for the ballistic collective group delay (CGD) of all the particles on the Fermi surface in graphene. First, we reveal that lateral Goos-Hanchen (GH) shifts along barrier interfaces contribute an inherent component in the individual group delay (IGD). Then, by linking the complete IGD to spin precession through a dwell time, we suggest that the CGD and its GH component can be electrostatically measured by the conductance difference in a spin precession experiment under weak magnetic fields. Such an approach is feasible for almost any Fermi energy. We also indicate that it is a generally nonzero self-interference delay that relates the IGD to the dwell time in graphene.