Milestones

Columbia professors James Hone (mechanical engineering) and Cory Dean (physics), together with UVA professor Avik Ghosh (electrical and computer engineering), co-authored a study, “Electron optics with p-n junctions in ballistic graphene,” that has been included in Physics World’s Top Ten Breakthroughs of 2016. The researchers directly observed—for the first time—negative refraction for electrons passing across a boundary between two regions in a conducting material. First predicted in 2007, this effect has been difficult to confirm experimentally. The team was able to observe the effect in graphene, demonstrating that electrons in the atomically thin material behave like light rays, which can be manipulated by such optical devices as lenses and prisms. Their findings, published in Science (9/30/2016), could lead to the development of new types of electron switches, based on the principles of optics rather than electronics. (December 13, 2016)



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