American Scientist

To the Editors:

I found the article by Drs. Franke-Arnold and Arnold ("Twisting Light to Trap Atoms," May-June) to be extremely interesting. I am a mathematical and theoretical physicist working at present on generalized models of quantum computation and quantum algorithms. In our proposed "spin network quantum simulator," published in Annals of Physics in 2005, basic unitary gates are represented by recoupling between alternative (binary coupled) schemes of pure many-angular momentum states (not restricted to spin 1/2 qubits). I think that the experimental setting you are working on could be looked at as a possible physical implemen-tation of this kind of simulator.

Annalisa Marzuoli
University of Pavia, Italy

Dr. Franke-Arnold responds:

Dr. Marzuoli draws similarities between our research and her own work on quantum information protocols. Orbital angular momentum of light is a convenient testing ground for quantum information in higher dimensions, so it might be interesting to devise experiments to try to confirm her work.