



@article {1221,
	title = {Universal computation by multi-particle quantum walk},
	journal = {Science},
	volume = {339},
	year = {2013},
	month = {2013/02/14},
	pages = {791 - 794},
	abstract = {  A quantum walk is a time-homogeneous quantum-mechanical process on a graph
defined by analogy to classical random walk. The quantum walker is a particle
that moves from a given vertex to adjacent vertices in quantum superposition.
Here we consider a generalization of quantum walk to systems with more than one
walker. 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. Multi-particle
quantum walk includes a broad class of interacting many-body systems such as
the Bose-Hubbard model and systems of fermions or distinguishable particles
with nearest-neighbor interactions. We show that multi-particle quantum walk is
capable of universal quantum computation. Since it is also possible to
efficiently simulate a multi-particle quantum walk of the type we consider
using a universal quantum computer, this model exactly captures the power of
quantum computation. In principle our construction could be used as an
architecture for building a scalable quantum computer with no need for
time-dependent control.
},
	doi = {10.1126/science.1229957},
	url = {http://arxiv.org/abs/1205.3782v2},
	author = {Andrew M. Childs and David Gosset and Zak Webb}
}
