[quantum-info] PIQuDos seminar Wed Sept 10: Jeongwan Haah

[Gus Gutoski]

Reminder: PIQuDos seminar by Jeongwan Haah on Wed Sept 10 at 16:00 in
the Time room.

On Wed, Sep 3, 2014 at 11:12 PM, Gus Gutoski
<ggutoski at perimeterinstitute.ca> wrote:
> Please join us on Wednesday, September 10 at 4pm in the Time room for
> a quantum information seminar by Jeongwan Haah.
>
> Title:  An invariant of topologically ordered states under local
> unitary transformations
> Speaker: Jeongwan Haah
>
> Abstract: For an anyon model in two spatial dimensions described by a
> modular tensor category, the topological S-matrix encodes the mutual
> braiding statistics, the quantum dimensions, and the fusion rules of
> anyons. It is nontrivial whether one can compute the topological
> S-matrix from a single ground state wave function. In this talk, I
> will show that, for a class of Hamiltonians, it is possible to define
> the S-matrix regardless of the degeneracy of the ground state. The
> definition manifests invariance of the S-matrix under local unitary
> transformations (quantum circuits). The defined S-matrix depends only
> on the ground state, in the sense that it can be computed by any
> Hamiltonian in the class of which the state is a ground state. This
> property, together with the local unitary invariance implies that any
> quantum circuit that connects two ground states of distinct
> topological S-matrices must have depth that is at least linear in the
> diameter of the system. A higher dimensional analog is
> straightforward. [arXiv:1407.2926]
>
> Date: Wednesday, September 10, 2014.
> Time: 16:00
> Location: Time Room