ArXiv identifier: 
0903.0543
Speakers: 
Giulio Chiribella
Authors: 
A. Bisio, G. Chiribella, G. M. D'Ariano, S. Facchini, P. Perinotti

We prove that the optimal strategy to store an unknown group transformation into a quantum memory is to apply the available uses in parallel on a suitable entangled state. The optimal retrieving strategy is the incoherent, ``measure-and-rotate'' strategy, in which the quantum memory is measured and a unitary depending on the outcome is performed. The same result holds for approximate re-alignment of reference frames for quantum communication.

The National Quantum Information Centre of Gdansk (NQuantIC), together with the University of Gdansk is seeking an experimentalist interested in a position (professor or senior researcher) in experimental quantum optics and/or quantum information technology.

The Quantum Information Theory Group QUIT in Pavia (www.qubit.it) is searching for highly motivated postdoctoral scientists to join the young and dynamic research team led by Giacomo M. D'Ariano at the "A. Volta" Physics Department of the University of Pavia (www.unipv.it)

Postdoctoral Research Associate (Fixed term until 31 August 2012)
Mathematical Quantum Control
Institute of Mathematics and Physics
Grade 7: £30,594 - £35,469
Applications are invited for a postdoctoral research associate position at Aberystwyth University. The successful candidate will work on an EPSRC funded project on theoretic methods applied to quantum control, and will work with the Quantum Open Systems and Control research group at Aberystwyth.

ArXiv identifier: 
0905.2942
Speakers: 
Cesar A. Rodriguez-Rosario
Authors: 
Cesar A. Rodriguez-Rosario, James D. Whitfield, Alan Aspuru-Guzik

We introduce the quantum stochastic walk (QSW), which determines the evolution of generalized quantum mechanical walk on a graph that obeys a quantum stochastic equation of motion. Using an axiomatic approach, we specify the rules for all possible quantum, classical and quantum-stochastic transitions of a vertex as defined from its connectivity. We show how the family of possible QSW encompasses both the classical random walk (CRW) and the quantum walks (QW) as special cases, but also includes more general probability distributions.