Observation of topological Uhlmann phases with superconducting qubits


Date

2018

Publication Type

Journal Article

ETH Bibliography

yes

Citations

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Data

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.

Publication status

published

Editor

Book title

Volume

4

Pages / Article No.

10

Publisher

Nature

Event

Edition / version

Methods

Software

Geographic location

Date collected

Date created

Subject

Organisational unit

03720 - Wallraff, Andreas / Wallraff, Andreas check_circle

Notes

Funding

150046 - Exploring Geometric Effects and Geometric Gates with Superconducting Circuits (SNF)

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