Publication:
Observation of topological Uhlmann phases with superconducting qubits

Loading...
Thumbnail Image
Full text at PDC
Publication Date
2018-02-12
Advisors (or tutors)
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
Nature publishing group
Citations
Google Scholar
Research Projects
Organizational Units
Journal Issue
Abstract
Topological insulators and superconductors at finite temperature can be characterized by the topological Uhlmann phase. However, a direct experimental measurement of this invariant has remained elusive in condensed matter systems. Here, we report a measurement of the topological Uhlmann phase for a topological insulator simulated by a system of entangled qubits in the IBM Quantum Experience platform. By making use of ancilla states, otherwise unobservable phases carrying topological information about the system become accessible, enabling the experimental determination of a complete phase diagram including environmental effects. We employ a state-independent measurement protocol which does not involve prior knowledge of the system state. The proposed measurement scheme is extensible to interacting particles and topological models with a large number of bands.
Description
© All authors. M.A.M.D., A.R. and O.V. thank the Spanish MINECO grant FIS2012-33152, a “Juan de la Cierva-Incorporación” reseach contract, the CAM research consortium QUITEMAD+ S2013/ICE-2801, the U.S. Army Research Office through grant W911NF-14-1-0103, Fundación Rafael del Pino, Fundación Ramón Areces, and RCC Harvard. S.G., A.W. and S.F. acknowledge support by the Swiss National Science Foundation (SNF, Project 150046).
Unesco subjects
Keywords
Citation
Collections