Since the Bekenstein-Hawking black hole entropy made its appearance in the seventies, the idea that the ultimate number of degrees of freedom in a region depends on the area of its boundary began to gain currency. The idea sounds surprising. Entropy measures the number of degrees of freedom (“the stuff”). Normally we expect its amount to grow with volume, as with the amount of stuff we can squeeze into a bag or a box.  The research in string theory and loop quantum gravity allowed to derive the “area laws” for black hole entropy  from the first principles, with only a small amount of additional assumptions. At the same time the black hole thermodynamics was developed.

2 new Postdoc posts are now available in the QISS group. The posts are to work in the area of quantum information theory: More specifically, from the advertising material:

 

I just caught up with one of my 2007 Honours students, James Freckleton who did an Honours project with me on Quantum Games. What is that you ask? There is a lot written about quantum games. People seem to have made much hullabaloo that the quantized games give different paybacks than the classical games...but of course...the quantum game is a completely different game and why should it not give different results? James an

 

In this paper we study adiabatic information transport along a chain of quantum dots. Adiabatic operations as well as transportation have inherently the advantage of being relatively robust to errors in the control parameters. Since experimentalist have a hard time controling tiny quantum particles precisely, this property is extremely important. The qubit (quantum bit) is transported via time-dependant tunneling between adjacent quantum dots.

There is however a second source of errors which is due to the environment of the quantum particle. Here we model two different environmentally induced errors and study under which circumstances the adiabatic transport yields a high fidelity.

Quantum random walks have been studied a lot worldwide to see if they can provide a type of quantum algorithm. One normally compares the quantum random walk with a classical drunken sailor walk (whats this? See www.youtube.com/watch or really en.wikipedia.org/wiki/Random_walk). One set of intriguing result

Danny's paper on Physical accessibility of non-completely positive maps has just been accepted to Phys. Rev. A

A very late congratulations to Peter Brooke who has had a single-author paper accepted to PRA on Decoherence-free quantum-information processing using dipole-coupled qubits.

The paper "Anyonic interferometry and protected memories in atomic spin lattices" has been published in Nature Physics.