Nice observation. I believe there was a recent paper that touches on this topic: http://phys.org/news/2012-03-quantum-physics-matrix-efficient.html http://phys

Nice observation. I believe there was a recent paper that touches on this topic: http://phys.org/news/2012-03-quantum-physics-matrix-efficient.html http://phys.org/news/2012-03-quantum-physics-matrix-efficien... http://www.nature.com/ncomms/journal/v3/n3/full/ncomms1761.html http://www.nature.com/ncomms/journal/v3/n3/full/ncomms1761.h...