Quantum Physics

I gave a talk today for a group of local home-school students and parents, on the essential elements of quantum physics. The idea was to give them a sense of what sets quantum mechanics apart from other theories of physics, and why it's a weird and wonderful thing. The title is, of course, a reference to How to Teach Physics to Your Dog, and the second slide was an embedded version of the Chapter 3 reading. I set the talk up to build toward the double-slit experiment with electrons, using the video of the experiment made by Hitachi. Here's the talk on SlideShare: What Every Dog Should Know…
There have been a bunch of stories recently talking about quantum effects at room temperature-- one, about coherent transport in photosynthesis , even escaped the science blogosphere. They've mostly said similar things, but Thursday's ArxivBlog entry had a particular description of a paper about entanglement effects that is worth unpacking: Entanglement is a strange and fragile thing. Sneeze and it vanishes. The problem is that entanglement is destroyed by any interaction with the environment and these interactions are hard to prevent. So physicists have only ever been able to study and…
Quantum ghosts, dynamical decoupling, why a diamond is forever in quantum computing, transversal press, quantum phrases I can't grok, and quantum jumping. Quantum ghosts: here and here. These articles describe the work reported in Laing, Rudolph, and O'Brien. "Experimental Quantum Process Discrimination." Phys. Rev. Lett., 102, 160502 (2009) arXiv:0801.3831. The idea is to discriminate "non-orthogonal" quantum processes via the use of entanglement, which is cool. (I'm a bit surprised that this classic paper is not referenced.) Optimized dynamical decoupling performed in ions at NIST. Paper…