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There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
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Prof. Andrew Childs, University of Waterloo CANADA
Universal computation by multiparticle quantum walk
Quantum Institute Seminar Series
We show that multi-particle quantum walk is capable of universal quantum computation. A continuous-time multi-particle quantum walk is generated by a time-independent Hamiltonian with a term corresponding to a single-particle quantum walk for each particle, along with an interaction term. As in a previous single-particle construction, we use a discrete version of scattering theory to establish universality. However, we use a different encoding of quantum data and exploit interactions between particles to implement two-qubit gates. In our scheme, an n-qubit circuit with g gates can be simulated by the dynamics of O(n) particles evolving for time poly(n,g) on a planar graph of maximum degree 4 with poly(n,g) vertices. Thus our graphs are exponentially smaller (as a function of n) than those used in the single-particle construction, offering the potential for efficient implementation by a system with a physical degree of freedom for each vertex of the graph. Our results apply to a broad class of multi-particle quantum walk Hamiltonians, including the Bose-Hubbard model and models with nearest-neighbor interactions for fermions and distinguishable particles.
Based on joint work with David Gosset and Zak Webb.
For more information contact Prof. Ken Brown (404-385-3124).
Website: Andrew Childs
