# University of Vermont

## Department of Physics: Condensed Matter Theory Group

### Condensed Matter & Materials Science Seminar

## Thursday, November 29th, 2012

## Chris Herdman

Department of Physics, UVM## "Characterizing & engineering topological phases for quantum computation"

Quantum computation offers the possibility solving problems not solvable on traditional "classical" computers. However, the quantum information stored via standard quantum computer architectures is fragile and readily destroyed by noisy interactions with the environment. One design of a fault-tolerant quantum computer is based on exotic quantum phases of matter known as topological phases. Given the scarcity of topological phases in existing experimental systems, there is interest in identifying models that posses topological phases and generating them experimentally.

There are several roadblocks to building a topological quantum computer. First of all, topological order is due to a non-local quantum entanglement which cannot be identified by a local order parameter; because of this lack of broken conventional symmetry, topological phases are more difficult to identify than conventional phases. Additionally, known lattice models that posses topologically ordered ground states involve more than two-body interactions which don't naturally occur in experiments.

I will discuss approaches to numerically identify and classify topological phases as well as a route to generating topological phases in experimental systems. In particular, I will present numerical calculations of the topological entanglement entropy and fractal dimension of a topological phase of a quantum dimer model. Additionally, I will discuss a proposal to generate a topological phase in an experimental system of neutral atoms trapped in an optical lattice using stroboscopic Rydberg interactions.

Last modified November 27 2012 05:00 PM