Graphene is an ultrathin material made of pure carbon atoms arranged in a honeycomb structure of single atom thickness. It has unusually high electrical conductivity and has been investigated as the basis of new electronic devices. The high speed and fast response of the electrons in graphene also render this material an attractive candidate for controlling electromagnetic radiation in the terahertz and infrared, for which the electric field oscillates on a time scale shorter than a millionth of a millionth of a second. In this project, researchers at two academic institutions and the IBM Research Division aim to gain fundamental understanding into how electrons in graphene respond to electric fields on a very short time scale and to apply this understanding to develop new devices for controlling electromagnetic radiation in the terahertz and infrared. This spectral region, while very useful for purposes such as environmental monitoring, does not currently benefit from technologies comparable to those available for electromagnetic radiation at either higher or lower frequency. The project provides graduate and undergraduate students with training in an integrated academic-industrial research setting, allowing the students to benefit from the special expertise available in both types of institution.
This GOALI project investigates light-matter interactions of graphene and nanostructured graphene in the terahertz and infrared region of the electromagnetic spectrum. The goal of this research is to obtain a thorough understanding of the electronic response of graphene in the region of strong free-carrier processes and Pauli blocking of the interband transitions. These investigations on the fundamentals of the graphene electromagnetic response are complemented by studies of the use of graphene for basic building blocks of different photonic devices, including light modulators. The approaches include advanced spectroscopy techniques for characterization of both the static and dynamic response of graphene in the terahertz-infrared spectral region and the development of high-quality gated graphene samples and structures. In this integrated academic-industrial team, Professor Heinz leads the Fourier-transform infrared spectroscopy measurements of graphene materials and structures and also has responsibility for studies of photonics applications; Professor Shan leads the terahertz time-domain spectroscopy measurements and has responsibility for studies of the fundamental optical response of graphene; the industrial participants at IBM Research provide materials and fabrication capabilities and expertise.
