Coulomb correlation gap at magnetic tunneling between graphene layers

The strong suppression of equilibrium magnetic tunneling in a graphene/hBN/graphene heterostructure caused by the Coulomb correlation gap in the tunneling density of states has been found. Comparison has shown that the suppression of the equilibrium tunneling conductivity $G_0$ in a high magnetic field with a decrease in the temperature and the dependence of the observed gap width $\Delta$ on the filling factor of Landau levels $\nu$ are qualitatively similar to the respective results of similar experiments in GaAs heterostructures and has confirmed our hypothesis concerning the nature of the effect. However, the determined gap width $\Delta$ is much larger than those measured in all previous works in semiconductor heterostructures probably because the cyclotron energy in graphene is much higher than that in GaAs in the region of low Landau levels.