QIP – Post 2
The afternoon’s talks began with one by Rahul Jain. Frankly, it was another talk on computational complexity and, while interesting, is a topic for which I have a threshold that Jain’s talk exceeded.
Stefano Pironio followed Jain with a really cool discussion on using violations of Bell inequalities to generate random numbers (it included a great Dilbert cartoon in which Dilbert is introduced to a random number generator that is a horned monster that only spits out the number 9, the comment being that one can never really know if it is truly a random occurrence or not). Anyway, Pironio’s main idea is that violations of Bell inequalities are inherently random events. The first suggestion that this could be used for cryptography appeared in Roger Colbeck’s PhD thesis and embodies many aspects of no-signalling theorems. For his Bell estimator, Pironio did not use probabilities. The result is an expansion of randomness that, in conjunction with Chris Monroe’s group, was used to generate 42 new random bits.
The last talk of the afternoon was on the great paper by the collaboration I’m now calling Flame-broiled Bacon. Yes, I’m referring to the paper on adiabatic gate teleportation, some of which is discussed here by his co-authorness, The Pontiff (AKA The Bacon). Mr. Flame-broiled (i.e. Steve Flammia) used some nifty Metallica font to begin the talk, introducing the newly arrived Baby Bacon, named Max (someone in the audience suggested renaming him Min). Basically, the work Steve spoke about involved creating a spin triplet but in which two of the particles are entangled using a specific Hamiltonian. This entangled state is then transferred to the third + the middle one (I’m explaining this really badly). Essentially, the adiabatic evolution teleports the state of one to another. [Note that somewhere in here Steve made a possibly unintentional reference to the Jackson 5 (ABC, easy as 123) and missed a great opportunity to make a reference to ZZ Top courtesy of ZZ coupling. Hey, if you want a serious synopsis, go somewhere else. This blog highlights the hidden gems.] Their scheme has the advantage of being more robust to errors. Steve also highlighted an interesting implementation involving turning on and off B-fields in a way that can be used to teleport information., pointing out that this is a bit like a quantum transistor. The applied field introduces a quantum phase transition that yields a quantum logic gate. Instead of transferring current as in a transistor, this scheme transfers information!