Gouy phase of type-I SPDC-generated biphotons

Author(s)

de Brito, V, F. C. ; da Paz, I. G. ^[1] ; Hiller, Brigitte ^[2] ; Araujo, Jonas B. ^[3] ; Sampaio, Marcos ^[4]

Affiliation

^[1] de Brito, F. C., V, Univ Fed Piaui, Dept Fis, Campus Minist Petronio Portela, BR-64049550 Teresina, PI - Brazil

^[2] Univ Coimbra, CFisUC Dept Phys, P-3004516 Coimbra - Portugal

^[3] Univ Sao Paulo, Inst Fis, Dept Fis Matemat, CP 66-318, BR-05315970 Sao Paulo, SP - Brazil

^[4] de Brito, F. C., V, Univ Fed ABC, Dept Fis, Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Physics Letters A; v. 386, JAN 18 2021.
• Web of Science Citations: 0

Abstract

We consider a double Gaussian approximation to describe the wavefunction of twin photons (also called a biphoton) created in a nonlinear crystal via a type-I spontaneous parametric downconversion (SPDC) process. We find that the wavefunction develops a Gouy phase while it propagates, being dependent of the two-photon correlation through the Rayleigh length. We evaluate the covariance matrix and show that the logarithmic negativity, useful in quantifying entanglement in Gaussian states, although Rayleigh-dependent, does not depend on the propagation distance. In addition, we show that the two-photon entanglement can be connected to the biphoton Gouy phase as these quantities are Rayleigh-length-related. Then, we focus the double Gaussian biphoton wavefunction using a thin lens and calculate a Gouy phase that is in reasonable agreement with the experimental data of D. Kawase et al. published in Ref. {[}1]. (C) 2020 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 18/05948-6 - Perturbative and nonperturbative aspects of quantum field theory and relativistic quantum information
• Grantee: Marcos Donizeti Rodrigues Sampaio
• Support Opportunities: Scholarships abroad - Research