Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A simple nearest-neighbor two-body Hamiltonian system for which the
  ground state is a universal resource for quantum computation   We present a simple quantum many-body system - a two-dimensional lattice of
qubits with a Hamiltonian composed of nearest-neighbor two-body interactions -
such that the ground state is a universal resource for quantum computation
using single-qubit measurements. This ground state approximates a cluster state
that is encoded into a larger number of physical qubits. The Hamiltonian we use
is motivated by the projected entangled pair states, which provide a
transparent mechanism to produce such approximate encoded cluster states on
square or other lattice structures (as well as a variety of other quantum
states) as the ground state. We show that the error in this approximation takes
the form of independent errors on bonds occurring with a fixed probability. The
energy gap of such a system, which in part determines its usefulness for
quantum computation, is shown to be independent of the size of the lattice. In
addition, we show that the scaling of this energy gap in terms of the coupling
constants of the Hamiltonian is directly determined by the lattice geometry. As
a result, the approximate encoded cluster state obtained on a hexagonal lattice
(a resource that is also universal for quantum computation) can be shown to
have a larger energy gap than one on a square lattice with an equivalent
Hamiltonian.

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The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
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The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
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The categories of this paper are: adap-org
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The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
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The categories of this paper are: bayes-an