Infrared Hall Effect Studies in Graphene

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****NON-TECHNICAL ABSTRACT****Graphene, which consists of a single atomic layer of carbon atoms, has produced dramatic new physical phenomena and has potential for exciting technological applications, such as high speed transistors that could revolutionize electronics. This project will explore graphene in new ways by using polarized infrared light, with wavelengths up to several thousand times longer than visible light. The changes in the polarization of the light after interacting with graphene will help to resolve questions that have been left unanswered by other techniques as well as test new theoretical predictions. An example includes why/how graphene absorbs light at wavelengths that one would not expect. Furthermore, this project will test a theoretical predication that the polarization of transmitted light makes unusual jumps as a magnetic field is smoothly increased. In addition to providing new insights into this unusual and fundamentally important system and training PhD students, the project will reach out to under-represented groups in science by starting a radio-controlled flying club (~20 students) in a Buffalo public high school. The club will meet twice a month and each meeting will begin with hands-on lessons on how basic physics and advanced technology combine to make radio-controlled flight possible.****TECHNICAL ABSTRACT****Graphene, which consists of a single atomic layer of carbon atoms, has produced dramatic new physical phenomena, such as massles Dirac quasiparticles, and has potential for exciting technological applications, such as high speed room temperature ballistic transistors and tunable infrared detectors/sources. This project will explore graphene in new ways by using polarized infrared light (5-1200 meV) in magnetic fields up to 10T to probe the Hall effect of this chiral material. The changes in the polarization of the reflected and transmitted light will help to resolve questions that have been left unanswered by other techniques (absorption of radiation below the expected absorption edge, the asymmetry of electron and hole states in bilayer graphene, and the unusual temperature and magnetic field dependence of the dc Hall angle) as well as test new theoretical predictions (circular dichroism in the absence of a magnetic field in bilayer graphene and plateaus in the THz Hall response of graphene). In addition to providing new insights into this unusual and fundamentally important system and training PhD students, the project will reach out to under-represented groups in science by starting a radio-controlled flying club (~20 students) in a Buffalo public high school. The club will meet twice a month and each meeting will begin with hands-on lessons on how basic physics and advanced technology combine to make radio-controlled flight possible.