Rich Cyclotron Resonance Structure in Multilayer Graphene John Cerne, SUNY at Buffalo, DMR While much progress has been made in understanding monolayer and bilayer graphene, recent attention has shifted to graphene multilayers with stacking geometries that move beyond the typical stacking structure of natural graphite. This work is of fundamental interest since graphene’s electronic structure changes dramatically as adjacent layers are shifted or more layers are added, which has become increasingly important for basic research and applications. This work is further motivated by the nature of large-area, low-disorder multilayer graphene (e.g. epitaxial growth on SiC), which typically contains a mixture of multilayers with varying stacking order and thickness. In this work we use polarization-sensitive infrared ( meV) magneto-polarimetry to optically reveal the strong complex signatures of these mixed multilayers. Moreover, we experimentally probe the evolution of electronic structure for graphene as three-dimensionality is added to a purely two-dimensional system and show that magneto-polarimetry provides a foundation for contactless “fingerprinting” of heterogeneous, large-area graphene multilayers as well as other similarly complex materials Our work reveals over 18 cyclotron resonances up to magnatic fields B of 5 T, allowing us to identify more than four distinct types of graphene layer structures in a single sample; tests three theories on the magneto-optical structure of graphene multilayers; provides intra- and interlayer coupling strengths; yields a new way to measure the Fermi energy, which is responsible for the large polarization changes due to chiral asymmetry; and shows no evidence of an electron-hole band asymmetry, commonly seen in gated samples. This work has been sent out for review by Nature Communications. 18 different features are observed in SiC graphene film, with each form of graphene contributing a series of resonances, making it difficult to determine the composition of the film. a) b) By plotting the data in a) vs. 1/B and taking the Fourier transform, now each type of multilayer produces a single peak, making it very easy to determine the types of graphene present in the film. The peaks shift linearly with photon energy.

Exposing Buffalo public school students to science and technology through aviation John Cerne, SUNY at Buffalo, DMR The PI, in collaboration with UB's Liberty Partnership Program, organized a trip for approximately 20 Buffalo public school students and their parents to an air show at Niagara Falls, NY in September After seeing a radio-control flight demonstration by Dr. Cerne, the students and parents were taken to the day-long airshow, which featured the latest military jets and aerobatic airplanes as well as the US Air Force Thunderbird demonstration team. None of the students had ever been to an air show or seen a state-of-the-art jet fighter in flight, and this was a great opportunity to show them what science and technology have made possible as well as to encourage them to explore careers in aviation, engineering, public service, and science. The students have formed a radio- control flying club, which has been meeting every other Friday since December PI has expanded his educational website New videos have been added to demonstrate a real lockin amplifier and show how lockin detection, Fourier analysis, and Heisenberg’s Uncertainty Principle are conceptually connected. The videos can be found at: In September 2011 the PI received the SUNY Chancellor's Award for Excellence in Teaching and credits the educational activities that were part of his NSF CAREER Award as well as this grant for playing a significant role in earning that award. Students from Buffalo public schools attended an air show at Niagara Falls on 9/11/11 as part of the PI’s outreach program that uses aviation to illustrate the wonders of science and technology. One of several videos posted by the PI in July This video shows how a lockin amplifier can detect a small signal buried in a much larger background of noise. Students flying solo at one of the RC Club meetings.