The last day of QIP in Santa Fe. Also note that Joe has posted some nice notes on additivity on his blog: part I and part II. Oh, and QIP next year will be in Zurich, and QIP the year after next will be in Singapore.

### Lluis Masanes, “Towards device-independent security in QKD”

Paper: arXiv:0807.2158. I cam in late, so was a bit lost. But basically Lluis talked about secret key distillation under weaker assumptions than just assuming quantum theory. It seems that one an do secret key distillation from accessing the correlations that violate Bell inequalities under the assumption of no signaling.

### Amnon Ta-Shma, “Short seed extractors against quantum storage”

Amnon talked about the paper arXiv:0808.1994.

### Jop Briet (speaker), Harry Buhrman, and Ben Toner, “A generalized Grothendieck inequality and entanglement in XOR games”

Dude I need LaTeX support in scienceblogs. Jop talked about a new Grothendieck’s type inequality (see the paper arXiv:0901.2009 for the definition.) This can then be used to show that the amount of entanglement required to maximally violate a Bell inequality must depend on the number of measurements (not just the number of measurement outcomes.)

### Dejan Dukaric, Manuel Forster, Severin Winkler, and Stefan Wolf , “On non-locality distillation”

At this point my brain was full.

### Gilles Brassard, Louis Salvail, and Alain Tapp, “Key distribution and oblivious transfer à la Merkle”

### Robert König, Renato Renner, and Christian Schaffner, “The operational meaning of min- and max-entropy”

### Matthias Christandl, Dejan Dukaric, Robert König, and Renato Renner, “Postselection-technique with applications to quantum cryptography and the parallel repetition problem”

### Robert König (speaker), Ben Reichardt, and Guifre Vidal, “Exact entanglement renormalization for string-net models”

Here Robert described his work on Levin and Wen’s string net models. The main result is that the Levin and Wen models can be thought about as arising from the requirement of scale invariant. In particular they show how these models have ground states which are efficiently describable by multi-scale entanglement renormalization ansatz states. Paper here: arXiv:0806.4583. I like this paper a lot.

### Aram Harrow and Richard Low (speaker), “Efficient quantum tensor product expanders and k-designs”

It would be nice to efficiently implement random unitaries sampled uniformly with respect to Haar measure. This is hard. However often we want to construct methods for sampling random unitaries which give things like random unitaries. Here they talk about the case where one wants to sample with respect to Haar measure which matches the first k moments of the Haar measure (a k-design). Aram and Richard present ways to do this efficiently by efficiently constructing a “k-copy tensor product expander.” Paper: arXiv:0811.2597.