20051122

Towards Fullerene-Based Quantum Computing Oxford In quant-ph 0511198, Benjamin et al. report on recent investigation of C60 arrays as a potential architecture for coherent quantum information processing. "Molecular structures appear to be natural candidates for a quantum technology: individual atoms can support quantum superpositions for long periods, and such atoms can in principle be embedded in a permanent molecular scaffolding to form an array [...] Here we report our efforts, both experimental and theoretical, to create such a technology based on endohedral fullerenes or ‘buckyballs’. We describe our successes with respect to these criteria, along with the obstacles we are currently facing and the questions that remain to be addressed."




Fullerene Molecules Left: A model of N@C60, illustrating that the nitrogen atom sits at the centre of the fullerene cage. Its electron wavefunction lies almost entirely inside, extending on the cage with only a 2% overlap. Right: The ‘peapod’ nanotube contains fullerenes packed in a pseudo-helical phase.

20051101

Efficient evaluation of decoherence rates in complex Josephson circuits IBM Watson Theoretical analysis of the variables contributing to decoherence in Josephson flux qubits has led to order-of-magnitude extensions of coherence time in these circuits over recent years, assisting in both the design phase and control parameter optimization for increasingly-complex qubit circuitry. In cond-mat 0510843, DiVincenzo, Brito and Koch perform a complete quantitative analysis of the decoherence properties of a Josephson flux qubit, exploring relaxation and dephasing times from two different control circuits along an optimal line in the space of applied fluxes.