Clash of the superconducting gate-model giants…

Flux qubits have been basking in the limelight recently…. two papers appearing on the ArXiv within a day of each other. Both papers investigate initialising, controlling and probing entangled states of a 3-qubit system:

Preparation and Measurement of Three-Qubit Entanglement in a Superconducting Circuit

Generation of Three-Qubit Entangled States using Superconducting Phase Qubits

Are Yale and SB going head-to-head in a gate-model phase/flux qubit battle? Looks like it…But who will win? Who has the highest T2?! Place your bets now!

More interestingly, this means we have yet another datapoint on the graph of number of successfully entangled sc gate model qubits versus time (in years). Presumably with 3 data points we can roughly gauge the scaling. I feel a plot may be required…and probably a log-lin scale.

Pointers toward the future of Quantum Computing…

I got quoted in this PhysicsWorld article:

Single atoms go transparent – PhysicsWorld April 21st 2010

The article was written in response to an ArXiv’ed paper from Nakamura’s group who investigate superconducting qubits (usually of the charge variety) in this case coupled to a microwave transmission line:

Electromagnetically induced transparency on a single artificial atom

From the article:

“Making an opaque material transparent might seem like magic. But for well over a decade, physicists have been able to do just that in atomic gases using the phenomenon of electromagnetically induced transparency (EIT). Now, however, this seemingly magical effect has been observed in single atoms – and in “artificial” atoms consisting of a superconducting loop – for the first time. “

I made the point in the article that combining flying qubits (basically entangled photons) which have the advantanges of long decoherence times and easy transportation of information, with solid-state implementations such as superconducting loops (good at storage and high-fidelity readout) would be a great step forwards in the generation of scalable architectures for quantum computing. Of course, I am slightly more biased towards the adiabatic QC approach at the moment (go figure) but there’s no reason why these developments couldn’t lead to some awesome hybrid quantum circuits involving a combination of gate model solid-state, AQC solid state and flying qubits. We just need to figure out how to put all the pieces together.

Watch my IOP talk – Building Quantum Computers – now on YouTube

You may remember a while back I mentioned that I’d put the video of my IOP talk up online. Well here it is. Thanks go to my kind colleague Dom for editing and posting these videos. Here is the first installment. I have posted links to the other 6 parts below. The talk is aimed at a general audience. It was given to a class of about 80 pupils of ages 14-18, and their teachers, although it is suitable for anyone who is interested in Physics, superconductors, superconducting processors and quantum computing. I apologise that the question and answer session (in parts 6 and 7) is a little difficult to hear, as the room was not set up to record audio in this way.
I’ll be putting a permanent link to this talk in the Resources section at some point soon. The slides are already available there if anyone wishes to look at them in more detail. Comments and feedback appreciated… Enjoy!

Part 2
Part 3
Part 4
Part 5
Part 6
Part 7