The Quantum Pontiff

So many times scientists are very harsh on science journalists. Thus it is refreshing to see this article in the MIT Technology Review by Jason Pontin on D-Wave’s recent Orion quantum computer. The article includes an interview with D-Wave’s Geordie Rose by Pontin which is rather refreshing mostly for the fact that Pontin pulls out the PCP theorem on Geordie (Gunslinging computer scientists come equiped with the PCP theorem strapped to their belts. Only recently were the schematics for how to build this gun made accessible to mere mortals like us physicists.) The article seems rather fair to me, airing both Geordie’s views as well as asking the hard questions, includes criticisms from Scott and Umesh Vazirani, as well as a more moderate view from Seth Llloyd. Whether you are satisfied with the answers Geordie gives, of course, is a different matter! For example, me I don’t think that the current setup they have scales if they continue with the same setup they have here (energy gap goes like one over problem size, I might buy that thermalizing helps a bit, but am extremely skeptical when the energy from the environment will swamp the energy spectrum), but this is different from believing that it’s not possible to modify the path they are taking to actually scale their system.
Update: Here is the New York Times version of the article, where, sadly the PCP theorem has been removed. Sad, I mean all the latte-sipping Volvo-driving lefties I know can speak elegantly in an instancet about the PCP theorem and approximation algorithms.

Okay, so I’ve heard qubits and qutrits, but until recently hadn’t heard ququarts. More googling revealed qupents. Okay, then after a little more research I found an old 1999 paper which, while not containing a six level quantum system, did contain,

In particular, our protocol transfers entanglement from a pair of quantum correlated
light fields to a pair of trapped atoms in a process of quantum state exchange, or qusex.

Ahem.