@techreport{downs2002the, author = {Downs, Oliver B. and Attias, Hagai and Burges, Chris J.C. and Rounthwaite, Robert}, title = {The Tunnelling Salesman: Truncated Variational Approximations for Quantum Mechanical Global Optimization}, year = {2002}, month = {October}, abstract = {In this work we present a novel method for global optimization, exploiting the mathematics of quantum mechanics, and in particular the tunnelling phenomenon. We consider a quantum mechanical system with a single particle in a potential specified by the cost function of our optimization problem. We assume the groundstate of the system is localised to the global minimum of the potential function, a condition which can be assured by choosing the particle mass sufficiently large. We then approximate this groundstate using a variational approach to optimise an expansion in terms of a truncated basis set of harmonic oscillator wave functions. We show how to encode integer factoring and travelling salesman problems in terms of finding the global minimum of a quartic polynomial cost function. We demonstrate our quantum algorithm on one- and two-dimensional toy problems, and apply it to factoring biprimes with 10 bits.}, url = {http://approjects.co.za/?big=en-us/research/publication/the-tunnelling-salesman-truncated-variational-approximations-for-quantum-mechanical-global-optimization/}, pages = {9}, number = {MSR-TR-2002-100}, }