Southwest Quantum Information and Technology

Optimal recognition of exact free-fermion solutions for spin models

Presenting Author: Adrian Chapman, University of Sydney
Contributing Author(s): Steven T. Flammia

Finding exact solutions to spin models is a fundamental problem of many-body physics. A workhorse technique for many such exact solution methods is mapping to an effective description of noninteracting particles. The paradigmatic example of this method is the exact solution of the one dimensional XY model by mapping to free fermions via the Jordan-Wigner transformation. We connect the general problem of recognizing models which can be exactly solved in this way to the graph-theoretic problem of recognizing line graphs, which has been solved optimally. Our solution method captures an entire class of spin models which can be described by dynamical fermions coupled to Pauli symmetries. We give an example of a previously unsolved spin model and demonstrate its exact solution by our method. We close by showing how these techniques can be used to design new fermion-to-qubit mappings.

(Session : from 5:00pm - 7:00pm)