Quantum Initiative: Quantum Lunch

The Quantum Lunch is regularly held on Thursdays in the Theoretical Division Conference Room, TA-3, Building 123, Room 121.

The organizing committee includes Malcolm Boshier (P-21), Lukasz Cincio (T-4), Diego Dalvit (T-4), Changhyun Ryu (P-21) , Nikolai Sinitsyn (T-4), Rolando Somma (T-4), Yigit Subasi (T-4), Christopher Ticknor (T-1), and Wojciech Zurek (T-4).

For more information, or to nominate a speaker, contact Yigit Subasi or Lukasz Cincio.

To add your name to the Quantum Lunch email list, contact Kacy Hopwood.

Thursday, February 15, 2018
12:30 PM - 2:00 PM

Speaker: Anna Francuz (Jagiellonian University)

Technical Host: Lukasz Cincio

TOPIC: Determining topological order with tensor networks

Abstract
Topological order is a key ingredient of topological quantum computation. It gained recognition after it was realized, thanks to Alexei Kitaev, that quantum computational models can be written in the language of condensed matter systems. The most celebrated example among them is the so called toric code. In my talk, after the introduction to tensor networks and basics of topologically ordered states, I will present a method of extracting information about the topological phase starting from a ground state of a lattice Hamiltonian. Using the tensor network formalism I will show how to obtain topological S and T matrices, encoding the mutual statistics and self-statistics of emergent anyons. They determine the topological phase unequivocally and in that sense they can be thought of as some kind of non-local order parameter of topological phases of matter. I will show that 2D tensor network, called Projected Entangled Pair States, allows to analyze systems that are beyond the reach of the state-of-the-art 2D DMRG method due to long correlation length.