The electron has an intrinsic spin angular momentum of 1/2, measured in units of the reduced Planck constant �. Dirac demonstrated that the origin of this "classically indescribable" internal quantum number is intimately related to the structure of spacetime. The low energy elec-tronic excitations of graphene also have an internal quantum number, called pseudospin, that obeys the same algebra and results from the geometric properties of graphene's honeycomb lattice.

As part of an e�ort to build graphene transistors here at UCLA, we have calculated how graphene's low-energy electronic excitations interact with quantized oscillations of the electromagnetic �eld (i.e. photons). This calculation reveals that graphene's pseudospin is connected to a real spin angular momentum. Comparison with the original Dirac theory further suggests that the usual electron spin could also be the low-energy signature of quantized space. While testing this conjecture for the electron might involve prohibitively large energy scales, experi-ments that will probe the connection between discretized space and intrinsic spin in graphene are currently being developed in our labora-tory.

ColloquiumThursday, April 8, 2010

4:00 pm Room 1-434

Re�eshments at 3:30 pm

B.C. (Chris) Regan,UCLA Condensed Matter

The Department of Physics & Astronomy

Space Quantization and the Graphene Transistor

Design: maryjo design