Computational phases of quantum matter

Condensed Matter Seminars

Speaker: Robert Raussendorf, SBQMI / PHAS, UBC
Date & Time: Thu, 2017-11-09 14:00 - 15:00
Location: AMPEL #311
Local Contact: Robert Raussendorf
Intended Audience: Graduate

In condensed matter physics, the essential properties of a physical system are determined by the phase in which it resides. Recent years have witnessed tremendous progress in the classification of physical phases, and it is thus pertinent to ask: What can we use quantum phases of matter for? Superconductivity is a classic example for a fundamental quantum phenomenon that finds a wide range of technological applications. It does not require fine- tuning of parameters; rather it is a property of a whole quantum phase.

In our recent work [1], [2], we demonstrate that one property which characterized quantum phases of matter is their usefulness for quantum computation.—This is a surprising connection between quantum physics and computer science.

Our results apply to the framework of symmetry-protected topological order (SPTO), in spatial dimension 1. In my talk, I will first cover some background material, namely measurement-based quantum computation (MBQC), MBQC and symmetry [Miyake], and MBQC and SPTO [Else et al.], and then describe our result.

Joint work with David Stephen, Dongsheng Wang, Abhi Prakash and Tzu-Chieh Wei.

[1] Stephen, DT; Wang, DS; Prakash, A; Wei, TC; Raussendorf, R, Computational Power of Symmetry- Protected Topological Phases, Phys. Rev. Lett 119, 010504 (2017).

[2] Raussendorf, R; Wang, DS; Prakash, A; Wei, TC; Stephen, DT, Symmetry-protected topological phases with uniform computational power in one dimension, Phys. Rev. A 96, 012302 (2017).