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Download fileNuclear-magnetic-resonance quantum calculations of the Jones polynomial
journal contribution
posted on 2013-12-03, 00:00 authored by Raimund Marx, Amr Fahmy, Louis Kauffman, Samuel Lomonaco, Nikolas Pomplun, John M. Myers, Steffen J. Glaser, Andreas Spörl, Thomas Schulte-HerbrüggenThe repertoire of problems theoretically solvable by a quantum computer recently expanded to include the
approximate evaluation of knot invariants, specifically the Jones polynomial. The experimental implementation of
this evaluation, however, involves many known experimental challenges. Here we present experimental results for
a small-scale approximate evaluation of the Jones polynomial by nuclear magnetic resonance (NMR); in addition,
we show how to escape from the limitations of NMR approaches that employ pseudopure states. Specifically, we
use two spin-1/2 nuclei of natural abundance chloroform and apply a sequence of unitary transforms representing
the trefoil knot, the figure-eight knot, and the Borromean rings. After measuring the nuclear spin state of the
molecule in each case, we are able to estimate the value of the Jones polynomial for each of the knots.