Inadequacy of von neumann entropy for characterizing extractable work
New Journal of Physics 13 (2011)
Abstract:
The lack of knowledge that an observer has about a system limits the amount of work it can extract. This lack of knowledge is normally quantified using the Gibbs/von Neumann entropy. We show that this standard approach is, surprisingly, only correct in very specific circumstances. In general, one should use the recently developed smooth entropy approach. For many common physical situations, including large but internally correlated systems, the resulting values for the extractable work can deviate arbitrarily from those suggested by the standard approach. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.Unification of quantum and classical correlations and quantumness measures
(2011)
Experimental demonstration of a unified framework for mixed-state geometric phases
EPL 94:2 (2011)
Abstract:
Geometric phases have been found in every major branch of physics and play an important role in mathematics and quantum computation. Here, we unify two proposed definitions of the geometric phase in mixed states - Uhlmann's phase and Sjöqvist's phase - in a new formalism based on interferometry and further provide an experimental demonstration in NMR. This is also the first experimental measurement of Uhlmann's geometric phase. © 2011 Europhysics Letters Association.Quantum phase transition between cluster and antiferromagnetic states
(2011)
Quantum Processes, Systems, and Information, by Benjamin Schumacher and Michael Westmoreland
Contemporary Physics Taylor & Francis 52:2 (2011) 168-168