Great piece on BBC about the new quantum computing venture at Oxford, which has just won £27 million in funding. Features a nice interview with my old PhD supervisor, Simon Benjamin

http://www.bbc.com/news/technology-30515236

I now have working!!!

This is just a quick post to announce the publication of a paper (click here) with Ingemar Bengtsson, Kate Blanchfield and Mark Howard. It has been chosen as an *IOP select* paper, which is nice. This is the first paper where I haven’t actually meet all the collaborators, so writing it was a new experience and I hope to meet them someday soon.

I’ve decided to take the plunge and experiment with twitter

Not many posts so far. Mostly I am still learning my way around the interface.

At the department today, Emiliano Cancellieri showed me a video that he and other group members had made (by a professional company) to help popularize and promote their research.

It is super flash!

rate topic vs. topic @

http://arxiv.culturomics.org/

LDPC codes probably don’t sound very exciting, but they are! They are essentially the quantum codes that are easy to implement. By “easy to implement” I mean that the required measurements only involve a limited number of qubits. In contrast, other approaches (e.g. concatenated codes) involve measurements with complexity that increases with computations size. The LDPC classification naturally includes all topological codes where these measurements are also constrained to a small local region of some lattice. Topological codes really have revolutionized quantum computing and essentially every proposal for quantum computing now involves some use of topological codes to protect against noise.

In the summer there was a conference on LDPC codes that I was unfortunately unable to attend. However, all the talks were recorded and can be found at:
http://www.perimeterinstitute.ca/video-library/collection/international-workshop-quantum-ldpc-codes
I’ve haven’t watched all of them yet, but am well past the half way mark. I really can’t recommend these talks enough as every one is a gem and the recording quality is fantastic.

It is exciting to see that Mark Howard, Joseph Emerson, and Joel Wallman have got their recent magic states and contextuality paper published in nature. It is an interesting result that show a connection between contextuality and having a negative Wigner function. It is pretty clear that having a positive Wigner function ensures a noncontextual model for all stabiliser measurements. What these guys have shown is the converse, that for any negativity in the Wigner function we can find stabiliser measurements that do not permit a noncontextual description. If your not familar with the idea of contextuality then I’d refer you the paper, but it is useful to note that non-locality (experiments violating Bell inequalities) is a specific kind of contextuality.

See here for press release.

After a few months at Sheffield I’ve got a couple of papers submitted to the arXiv, and just got access to sort out my “other” webpage over at the group website.

Last week I got back from visiting the Perimeter Institute, which is perhaps architecturally optimal for theoretical physics. Whilst there, I gave a talk on continuous variable Gaussification and entanglement distillation. I haven’t watched it myself (I was there) so please do let me know if it is horribly poor in any respect!

A year ago I gave a related (but more out of date) talk at Imperial, which I’ve also not viewed. After giving the talk at Imperial, I had some interesting discussions with Marco Genoni that lead to some new ideas we used in a more recent paper.