Comment on Quantum cat-stencil interference projection? What is this?

Sat, 17 Jan 2015 19:02:15 GMT

Hrm... reading the paper, it does look like NL1 goes from |a> to |cd> instead of |c> + |d>, This is going to move all the numbers around, but you'll still find that it works as a bomb detector. The yellow coming out of the left non-interacting-with-bomb path only interferes with the yellow from the right-and-mid path when the bomb is a dud.

Just to be sure, I tried my hand at converting it into a logic circuit. Here's what I get:

Having it create both the red and yellow photon, instead of either-or, seems to have improved its function as a bomb tester back up to the level of the naive bomb tester. Half of the live bombs will explode, a quarter will trigger g, and the other quarter will trigger h. None of the dud bombs will explode or trigger g; all of them trigger h. Anytime g triggers, you've found a live bomb without exploding it.

If you're going to point out another minor flaw, please actually go through the analysis to show it stops working as a bomb tester. It's frustrating for the workload to be so asymmetric, and hints at motivated stopping (and I suppose motivated continuing for me).

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