Proposal for automated transformations on single-photon multipath qudits

Autor(es)

Baldijao, R. D. ; Borges, G. F. ; Marques, B. ; Solis-Prosser, M. A. ; Neves, L. ; Padua, S.

• Tipo de documento: Artigo Científico
• Fonte: PHYSICAL REVIEW A; v. 96, n. 3, p. 13-pg., 2017-09-18.

Resumo

We propose a method for implementing automated state transformations on single-photon multipath qudits encoded in a one-dimensional transverse spatial domain. It relies on transferring the encoding from this domain to the orthogonal one by applying a spatial phase modulation with diffraction gratings, merging all the initial propagation paths by using a stable interferometric network, and filtering out the unwanted diffraction orders. The automation feature is attained by utilizing a programmable phase-only spatial light modulator (SLM) where properly designed diffraction gratings displayed on its screen will implement the desired transformations, including, among others, projections, permutations, and random operations. We discuss the losses in the process which is, in general, inherently nonunitary. Some examples of transformations are presented and, considering a realistic scenario, we analyze how they will be affected by the pixelated structure of the SLM screen. The method proposed here enables one to implement much more general transformations on multipath qudits than is possible with a SLM alone operating in the diagonal basis of which-path states. Therefore, it will extend the range of applicability for this encoding in high-dimensional quantum information and computing protocols as well as fundamental studies in quantum theory. (AU)

• Processo FAPESP: 16/24162-8 - Darwinismo quântico e contextualidade
• Beneficiário: Roberto Dobal Baldijão
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 14/27223-2 - Controle de informação quântica com variáveis contínuas de feixes de luz
• Beneficiário: Breno Marques Goncalves Teixeira
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado