Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Japanese Journal of Applied Physics

Observation of Biexciton-Resonant Hyper-Parametric Scattering in SiO2/CuCl Layered Structures

Masaaki Nakayama, Takashi Nishioka, Shuji Wakaiki, Goro Oohata, Kohji Mizoguchi, DaeGwi Kim, Keiichi Edamatsu

Published Mar 1, 2007• 6 citations
Publisher

Abstract

We have prepared SiO 2 /CuCl layered structures and investigated the structural and optical properties, focusing on the observation of biexciton-resonant hyper-parametric scattering that is a promising process to generate entangled photons. A crystalline CuCl film, which is the active layer, was grown on an Al 2 O 3 substrate by a vacuum deposition method, and then an amorphous SiO 2 film as the passivation layer for hygroscopic CuCl was prepared by an rf-magnetron sputtering method. X-ray diffraction patterns and optical spectra of excitons indicate that the growth of the SiO 2 -passivation layer does not degrade the crystallinity of the underlying CuCl thin film. It has been demonstrated that the biexciton-resonant hyper-parametric scattering is clearly observable in the SiO 2 /CuCl layered structure.

DOI
10.1143/jjap.46.l234

Related papers

Photon Statistics Analysis of Entangled Photon Pairs via Biexciton Resonant Hyper-Parametric Scattering

Yasufumi YAMAMOTO, Goro Oohata, K. Mizoguchi

We have investigated the quantum statistics of entangled photon pairs generated from biexcitons in CuCl single crystals via resonant hyper-parametric scattering. The generation of multi-photon pairs has been first observed under the high excitation power.

Nonlinear Optics•Jan 1, 2013•0 citations

Generation of entangled-photon pairs from biexcitons in CuCl thin films: Nano-to-bulk crossover regime

Motoaki Bamba, Hajime Ishihara

We have constructed a theoretical framework of biexciton-resonant hyperparametric scattering for pursuit of high-power and high-quality generation of entangled-photon pairs. Our framework is applicable to the nano-to-bulk crossover regime where the center-of-mass motions of excitons and biexcitons are confined and material surroundings and the polarization correlation of generated photons can be considered. We have analyzed the generation of ultraviolet entangled photons from CuCl film with and without dielectric microcavity and revealed that in the nano-to-bulk crossover regime we generally get a high performance from the viewpoint of statistical accuracy and the generation efficiency can be enhanced by the optical cavity while maintaining the high performance. The nano-to-bulk crossover regime has a variety of degrees of freedom to control the entangled-photon generation, and the scattering spectra explicitly reflect quantized exciton-photon coupled modes in finite structures.

arXiv:1104.0374•Physical Review B•Jul 18, 2011•1 citation

Generation of entangled photons via biexciton-resonant hyper-parametric scattering

Goro Oohata, Ryōsuke Shimizu, Keiichi Edamatsu

We demonstrate the entangled photon pair generation via biexciton-resonant hyper parametric scattering in CuCl crystal. Quantum tomographic analysis of the polarization correlation measurements showed that the generated photon pairs had a high degree of polarization entanglement, in consequence of J=0 angular momentum of the biexciton state.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Apr 28, 2005•0 citations

Generation of entangled photons from biexcitons in a semiconductor

Goro Oohata, Keiichi Edamatsu

We demonstrate the first experimental realization of the entangled photon pair generation via biexciton-resonant hyper parametric scattering in CuCl crystal. Polarization correlation measurements and quantum tomographic analysis shows that the generated photon pairs have high degrees of polarization entanglement.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jan 11, 2005•0 citations

Evaluation of two-photon polarization density matrix of polarization-entangled photon pairs generated through biexciton resonant hyper-parametric scattering

Yasuo Yamamoto, Goro Oohata, Kohji Mizoguchi

We have investigated the excitation-power dependence of polarization-entangled photon pairs generated from a CuCl single crystal using biexciton resonant hyper-parametric scattering. The two-photon polarization density matrix of photon pairs generated from a CuCl single crystal maintained at 10 K was measured under different excitation powers. The measured two-photon polarization density matrix, which corresponds to the two-photon polarization state, changes with an increase in the excitation power. The evaluations of the tangle and the linear entropy obtained from the measured density matrix indicate that the two-photon polarization density matrix can be expressed as the mixed state of an ideal state and a totally mixed state, and the mixture ratio of the totally mixed state increases as the excitation density increases. The variations of the density matrix and the mixture ratio with the excitation power originate from the generation of the multiple photon pairs. Furthermore, a numerical calculation considering simultaneous detection efficiency was able to reproduce the experimental results.

arXiv:1801.00596•Journal of the Optical Society of America B•May 22, 2019•0 citations

Bose-Einstein statistical properties and condensation of excitonic molecules in CuCl

Nasser N. Peyghambarian, Lloyd L. Chase, A. Mysyrowicz

A comprehensive investigation of the optical properties of excitonic molecules in CuCl films is presented and discussed. The experimental work includes resonant two-photon absorption (TPA), observations of the resonantly excited biexciton emission, and optical pump-and-probe studies. The collision broadening of the TPA implies a collision rate \ensuremath{\sim}${10}^{\ensuremath{-}12}$ sec for the biexcitons, which is sufficiently rapid to establish a quasithermal equilibrium for the particles on a time scale that is short in comparison with the biexciton lifetime and the duration of the laser pump pulse. The biexciton luminescence line shapes obtained with resonant $\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}=0$ two-photon excitation have been fitted using a Bose-Einstein thermal distribution of biexcitons. The chemical potential obtained from the fits goes to zero as the biexciton density is increased at a fixed lattice temperature or if the lattice temperature is decreased at fixed density. The sharp luminescence features that are observed at high densities and low temperatures with single-beam, two-photon excitation are interpreted as resulting from a Bose-Einstein---condensed state of the biexcitons at twice the wave vector of the laser pumping photons. Further evidence for a condensed state is obtained from optical-probe measurements in which a small number of probe biexcitons is injected into the sample, with and without the presence of a condensed state produced by an intense laser pump beam. The luminescence of these injected probe biexcitons is modified in the presence of the pump beam such that it exhibits the sharp features of the emission from the condensed state. Measurements of optical gain and stimulated emission in the presence of the pump beam show that the redistribution of the probe luminescence does not result from those processes, but must involve a preferential redistribution of the probe particles in momentum space via collisions. Such a redistribution is expected when additional particles are added to a condensed system of bosons.

Physical review. B, Condensed matter•Feb 15, 1983•81 citations
We have prepared SiO 2 /CuCl layered structures and investigated the structural and optical properties, focusing on the observation of biexciton-resonant hyper-parametric scattering that is a promising process to generate entangled photons. A crystalline CuCl film, which is the active layer, was grown on an Al 2 O 3 substrate by a vacuum deposition method, and then an amorphous SiO 2 film as the passivation layer for hygroscopic CuCl was prepared by an rf-magnetron sputtering method. X-ray diffraction patterns and optical spectra of excitons indicate that the growth of the SiO 2 -passivation layer does not degrade the crystallinity of the underlying CuCl thin film. It has been demonstrated that the biexciton-resonant hyper-parametric scattering is clearly observable in the SiO 2 /CuCl layered structure.
We have constructed a theoretical framework of biexciton-resonant hyperparametric scattering for pursuit of high-power and high-quality generation of entangled-photon pairs. Our framework is applicable to the nano-to-bulk crossover regime where the center-of-mass motions of excitons and biexcitons are confined and material surroundings and the polarization correlation of generated photons can be considered. We have analyzed the generation of ultraviolet entangled photons from CuCl film with and without dielectric microcavity and revealed that in the nano-to-bulk crossover regime we generally get a high performance from the viewpoint of statistical accuracy and the generation efficiency can be enhanced by the optical cavity while maintaining the high performance. The nano-to-bulk crossover regime has a variety of degrees of freedom to control the entangled-photon generation, and the scattering spectra explicitly reflect quantized exciton-photon coupled modes in finite structures.
We have investigated the excitation-power dependence of polarization-entangled photon pairs generated from a CuCl single crystal using biexciton resonant hyper-parametric scattering. The two-photon polarization density matrix of photon pairs generated from a CuCl single crystal maintained at 10 K was measured under different excitation powers. The measured two-photon polarization density matrix, which corresponds to the two-photon polarization state, changes with an increase in the excitation power. The evaluations of the tangle and the linear entropy obtained from the measured density matrix indicate that the two-photon polarization density matrix can be expressed as the mixed state of an ideal state and a totally mixed state, and the mixture ratio of the totally mixed state increases as the excitation density increases. The variations of the density matrix and the mixture ratio with the excitation power originate from the generation of the multiple photon pairs. Furthermore, a numerical calculation considering simultaneous detection efficiency was able to reproduce the experimental results.
A comprehensive investigation of the optical properties of excitonic molecules in CuCl films is presented and discussed. The experimental work includes resonant two-photon absorption (TPA), observations of the resonantly excited biexciton emission, and optical pump-and-probe studies. The collision broadening of the TPA implies a collision rate \ensuremath{\sim}${10}^{\ensuremath{-}12}$ sec for the biexcitons, which is sufficiently rapid to establish a quasithermal equilibrium for the particles on a time scale that is short in comparison with the biexciton lifetime and the duration of the laser pump pulse. The biexciton luminescence line shapes obtained with resonant $\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}=0$ two-photon excitation have been fitted using a Bose-Einstein thermal distribution of biexcitons. The chemical potential obtained from the fits goes to zero as the biexciton density is increased at a fixed lattice temperature or if the lattice temperature is decreased at fixed density. The sharp luminescence features that are observed at high densities and low temperatures with single-beam, two-photon excitation are interpreted as resulting from a Bose-Einstein---condensed state of the biexcitons at twice the wave vector of the laser pumping photons. Further evidence for a condensed state is obtained from optical-probe measurements in which a small number of probe biexcitons is injected into the sample, with and without the presence of a condensed state produced by an intense laser pump beam. The luminescence of these injected probe biexcitons is modified in the presence of the pump beam such that it exhibits the sharp features of the emission from the condensed state. Measurements of optical gain and stimulated emission in the presence of the pump beam show that the redistribution of the probe luminescence does not result from those processes, but must involve a preferential redistribution of the probe particles in momentum space via collisions. Such a redistribution is expected when additional particles are added to a condensed system of bosons.