1201.4877 (Dominic V. Else et al.)

Symmetry-protected phases for measurement-based quantum computation    [PDF]

Dominic V. Else, Ilai Schwarz, Stephen D. Bartlett, Andrew C. Doherty

Ground states of spin lattices can serve as a resource for measurement-based
quantum computation. Ideally, the ability to perform quantum gates via
measurements on such states would be insensitive to small variations in the
Hamiltonian. Here, we describe a class of symmetry-protected topological orders
in one-dimensional systems, any one of which ensures the perfect operation of
the identity gate. As a result, measurement-based quantum gates can be a robust
property of an entire phase in a quantum spin lattice, when protected by an
appropriate symmetry.

View original: http://arxiv.org/abs/1201.4877