So I spent last week hanging out at D-Wave systems which was awesome. For anyone not in the know, they are (to the best of my knowledge) the only company pursuing the ambitious goal of building a large scale quantum computer.
Their architecture consists of superconducting flux qubits implemented in the framework of Adiabatic Quantum Computing (AQC). Most people think of the gate model when they envisage quantum computing, which consists of applying unitary evolution operators (rotations in the Bloch sphere) to single qubits and to entangled states of multiple qubits. AQC works a little differently, by slowly evolving the Hamiltonian of the system (slow in order to keep it in the ground state) from an initial Hamiltonian (where the ground state is easily prepared) to one where the ground state would encode the solution to a hard problem.
To compare, the gate model involves moving between states, and taking the system to higher energy levels. Remaining in the ground state means that you are always protected from sources of decoherence (i.e. nearby states) by an energy gap, which is a minimum at the point where the energies of the two Hamiltonians would classically intersect. However at this point the quantum mechanical explanation predicts an anticrossing of these states, and thus the appearance of the energy gap (hope I got that correct). I’m from an experimental gate model background, be kind 😀
They really are a unique company, and their experimental effort was impressive. (Of course so too was the theoretical side, but coming from an experimental background I could relate more to the cool kit and the data). I met some really fantastic people whilst I was there. Not to mention the fact that Vancouver is one of the most beautiful cities I have visited. Combine immense yet aesthetically pleasing skyscrapers, modern city living, a picturesque harbour with a mountain range backdrop, stunning forests and parks, beaches, amazing coffee, numerous outdoor sports opportunities and more seafood restaurants than you could possibly dream of, and the picture begins to take shape. They also have nutella ice-cream… Just thought I’d mention that.
To check out more about the company, you can read Geordie’s blog (he’s the CTO of D-Wave and a really cool guy) or visit the company link above.
Hopefully I’ll be able to report more on this topic in the future!