Autor(es)

Pires, Diego Paiva ; DeAzevedo, Eduardo R. ; Soares-Pinto, Diogo O. ; Brito, Frederico ; Filgueiras, Jefferson G.

• Tipo de documento: Artigo Científico
• Fonte: COMMUNICATIONS PHYSICS; v. 7, n. 1, p. 8-pg., 2024-05-02.

Resumo

The quantum speed limit (QSL) is a fundamental lower bound on the evolution time for quantum systems, and its tightness has been observed to be dependent on the properties of the physical process. However, experimental studies exploring the QSL in open quantum systems are still missing. Here, we studied geometric quantum speed limits of a qubit subject to decoherence in an ensemble of chloroform molecules in a Nuclear Magnetic Resonance experiment. We controlled the system-reservoir interaction and the spin relaxation rates by adding a paramagnetic salt, allowing the observation of both Markovian and non-Markovian open system dynamics for the qubit. We used two distinguishability measures of quantum states to assess the speed of the qubit evolution: the quantum Fisher information (QFI) and Wigner-Yanase skew information (WY). For non-Markovianity and low salt concentrations, we found crossovers between QSLs related to those metrics. The WY metric sets the tighter QSL for high concentrations and Markovian dynamics. We also show that QSLs are sensitive even to small fluctuations in spin magnetization. Quantum Speed Limit (QSL) is a lower bound on the time evolution for quantum systems. Still, experimental studies for open systems are few due to the lack of control over their environment's interaction. The authors control the qubitreservoir interaction in an ensemble of chloroform molecules, observing crossovers between different QSLs. (AU)

• Processo FAPESP: 17/03727-0 - Características quânticas de sistemas compostos: geometria, dinâmica e termodinâmica
• Beneficiário: Diogo de Oliveira Soares Pinto
• Modalidade de apoio: Auxílio à Pesquisa - Regular