Electric current shoots straight across a sheet of defect-free graphene with almost no resistance, a feature that makes the material highly attractive to engineers who would use it in things like touchscreens and other electronics, said Rice University theoretical physicist Boris Yakobson.
Image: A graphic by Rice researchers shows graphene growth via open-pentagon armchair edges, with atoms joining one by one to form the material’s familiar hexagonal lattice. The researchers analyzed the energies involved in graphene creation in a study that may help experimentalists grow better-quality graphene via chemical vapor deposition. © Yakobson Lab/Rice University
Image: Rice University researchers have come up with a set of calculations to predict how graphene grows in the process known as chemical vapor deposition. The graph set against an illustration of graphene growing on a nickel catalyst shows the initial energy barrier a carbon atom must overcome to join the bloom; subsequent atoms face an ever-smaller energy barrier until the process begins again for the next line. © Vasilii Artyukhov/Rice University
Vasilii I. Artyukhov, Yuanyue Liu, and Boris I. Yakobson: Equilibrium at the edge and atomistic mechanisms of graphene growth, In: PNAS, Vol. 109, No. 38, September 4, 2012, Pages 15136-15140, DOI:10.1073/ pnas.1207519109:
http://dx.doi.org/10.1073/pnas.1207519109
http://news.rice.edu/2012/09/04/every-atom-counts-in-graphene-formation/
Qubit-based computing exploiting spooky quantum effects like entanglement and superposition will speed up factoring and searching calculations far above what can be done with mere zero-or-one bits. To domesticate quantum weirdness, however, to make it a fit companion for mass-market electronic technology, many tricky bi-lateral and multilateral arrangements – among photons, electrons, circuits, cavities, etc. – need to be negotiated. A new milestone in this forward march: a Prince- ton-Joint Quantum Institute (JQI) collaboration announces the successful excitation of a spin qubit using a resonant cavity. The circuit, via the cavity, senses the presence of the qubit as if it were a bit of capacitance. This result points toward the eventual movement of quantum information over “bus” conduits much as digital information moves over buses in conventional computers.
Image: Hybrid quantum dot-superconducting resonator device. (a) Circuit schematic and micrograph of the hybrid device design. Scanning electron micrograph (b) and cross-sectional schematic view (c) of the nanowire double quantum dot (DQD). The left and right barrier gates (BL and BR), left and right plunger gates (L and R), and middle gate (M) are biased to create a double-well potential within the nanowire. The drain contact of the nanowire, D, is grounded, and the source contact, S, is connected to an antinode of the resonator, oscillating at a voltage VCavity. © Credit Petersson et. al.
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