1. Department of Electrical, Computer and Systems Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
2. Center for Materials, Devices and Integrated Systems, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
3. Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, USA