Quantum Wheatstone Bridge

Autor(es)

Poulsen, Kasper ; Santos, Alan C. ; Zinner, Nikolaj T.

• Tipo de documento: Artigo Científico
• Fonte: Physical Review Letters; v. 128, n. 24, p. 6-pg., 2022-06-13.

Resumo

We propose a quantum Wheatstone bridge as a fully quantum analog to the classical version. The bridge is a few-body boundary-driven spin chain exploiting quantum effects to gain an enhanced sensitivity to an unknown coupling. The sensitivity is explained by a drop in population of an entangled Bell state due to destructive interference as the controllable coupling approaches the unknown coupling. A simple criterion for the destructive interference is found, and an approximate expression for the width of the drop is derived. The sensitivity to the unknown coupling is quantified using the quantum Fisher information, and we show that the state of the bridge can be measured indirectly through the spin current. Our results are robust toward calibration errors and generic in the sense that several of the current state-of-the-art quantum platforms could be used as a means of realization. The quantum Wheatstone bridge may thus find use in fields such as sensing and metrology using near-term quantum devices. (AU)

• Processo FAPESP: 21/10224-0 - Processamento de informação quântica com íons de Rydberg aprisionados
• Beneficiário: Alan Costa dos Santos
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado
• Processo FAPESP: 19/22685-1 - Efeito de memória e transição do regime de desordem fraco ao forte
• Beneficiário: Alan Costa dos Santos
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado