2026-06-08T02:38:43Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/120402024-08-27T16:54:20Zcom_20.500.14352_14col_20.500.14352_15

Viyuela, O. Rivas, A. Gasparinetti, S. Wallraff, A. Filipp, S. Martín-Delgado Alcántara, Miguel Ángel 2023-06-17T12:26:45Z 2023-06-17T12:26:45Z 2018-02-12 2056-6387 10.1038/s41534-017-0056-9 https://hdl.handle.net/20.500.14352/12040 http://dx.doi.org/10.1038/s41534-017-0056-9 https://www.nature.com 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. eng https://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España Observation of topological Uhlmann phases with superconducting qubits journal article