Fast and virtually exact quantum gate generation in U(n) via iterative Lyapunov methods

Autor(es)

Pereira da Silva, Paulo Sergio ^[1] ; Silveira, Hector Bessa ^[2] ; Rouchon, Pierre ^[3]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Escola Politecn PTC, Sao Paulo - Brazil

^[2] Fed Univ Santa Catarina UFSC, Dept Automat & Syst, Florianopolis, SC - Brazil

^[3] Mines ParisTech, Ctr Automat & Syst, Paris - France

• Tipo de documento: Artigo Científico
• Fonte: International Journal of Control; v. 94, n. 4, p. 984-998, APR 3 2021.
• Citações Web of Science: 1

Resumo

A new approach called Reference Input Generation Algorithm (RIGA) is introduced for quantum gate generation. Let be the trajectory that is obtained in step , with . In step , is right-translated in order to displace to . The translated trajectory is used as a reference for a Lyapunov-based tracking control law, generating , and so on. A proof of the exponential convergence of to zero is provided for large enough. Two examples present numerical experiments regarding N coupled qubits. The first example considers N = 3 with a known minimum time . It presents excellent results for . The second example is a benchmark for the comparison between RIGA and GRAPE, considering a Hadamard gate for the systems with N = 2, 3, horizontal ellipsis , 10 qubits. The runtime of RIGA could be improved, and GRAPE was implemented in a faster CPU. However, RIGA presents results that are similar to GRAPE, with faster runtime in some cases, showing that the RIGA is indeed a promising algorithm. (AU)

• Processo FAPESP: 18/17463-7 - Controle de Portas Quânticas e de Conjuntos Contínuos de Equações de Bloch
• Beneficiário: Paulo Sergio Pereira da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Regular