Alternative axiomatizations of quantum theory and application for information processing
Reversibility is a desirable property for a theory. Without microscopic reversibility, information can be destroyed. Popescu and Rohrlich famously asked the question “is quantum theory (QT) the most non-local theory that obeys the no-signaliing principle”, and answered in the negative (the theory known as Boxworld being the answer). On the other hand, Boxworld contains no reversible entangling dynamics. Perhaps an even more pertinent question to ask would be “is quantum theory the most non-local reversible theory that obeys the no-signalling principle”. If the answer is yes, three pillars of modern physics (information cannot be destroyed, no-signalling and the breaking of Bell inequalities) would be enough to single out QT from other probabilistic theories. It is striking to note that to date there are no known theories other than QT that are reversible and non-local.
During my PhD project, I will try to characterise the properties of theories that can be reversible and non-local. In doing so I hope to determine if these properties, when taken together, are special properties of only a few theories or are quite general (as is the case with entanglement, teleportation, and so on...). I will also work on topics in quantum thermodynamics.
Criticality, factorization, and long-range correlations in the anisotropic XY model, Steve Campbell, Jonathan Richens, Nicola Lo Gullo, and Thomas Busch, Phys. Rev. A 88, 062305, Dec 2013