Methods and apparatus characterized by distinct operating modes are provided. A thin graphite material defined by graphene layers is supported on a silicon substrate. The graphite material is defined by edge sites at the interface with the silicon. The graphite material is characterized by electrical superconductive-like behavior at room-temperatures while electrical current flows there through in a first direction. The graphite material is further characterized by a transition to Ohmic behavior while electrical current flows there through in a second direction opposite to the first. Devices exhibiting diode-like behavior can be formed accordingly.