Bounds in sequential unambiguous discrimination of multiple pure quantum states

Sequential methods for quantum hypothesis testing offer significant advantages over fixed-length approaches, which rely on a predefined number of state copies. Despite their potential, these methods remain underexplored for unambiguous discrimination. In this work, we derive performance bounds for s...

ver descrição completa

Detalhes bibliográficos
Autores: Pérez Guijarro, Jordi, Pagès Zamora, Alba Maria|||0000-0002-7087-7014, Rodríguez Fonollosa, Javier|||0000-0002-0136-2586
Tipo de documento: artigo
Data de publicação:2025
País:España
Recursos:Universitat Politècnica de Catalunya (UPC)
Repositório:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglês
OAI Identifier:oai:upcommons.upc.edu:2117/446890
Acesso em linha:https://hdl.handle.net/2117/446890
https://dx.doi.org/10.22331/q-2025-11-20-1919
Access Level:Acceso aberto
Palavra-chave:Quantum hypothesis testing
Sequential methods
Àrees temàtiques de la UPC::Informàtica::Informàtica teòrica
Descrição
Resumo:Sequential methods for quantum hypothesis testing offer significant advantages over fixed-length approaches, which rely on a predefined number of state copies. Despite their potential, these methods remain underexplored for unambiguous discrimination. In this work, we derive performance bounds for such methods when applied to the discrimination of a set of pure states. The performance is evaluated based on the expected number of copies required. We establish a lower bound applicable to any sequential method and an upper bound on the optimal sequential method. The upper bound is derived using a novel and simple non-adaptive method. Importantly, the gap between these bounds is minimal, scaling logarithmically with the number of distinct states.