From dynamic relaxation measurements of the decay of supercurrents in
YBa2Cu3O7-delta films with thicknesses between 1.2 and 150 nm we deter
mine the correlation length L(c)(0) (the length of the tunneling vorte
x segment at T=0 K) to be 2.2 nm and show that quantum creep occurs in
a transition regime where Hall tunneling is as important as dissipati
ve tunneling.