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

arXiv:2409.19227 · Scientific Reports

Coherence analysis of local randomness and nonlocal correlation through polarization-basis projections of entangled photon pairs

Byoung Seung HAM

Published Mar 31, 2025• 0 citations
arXivHTMLPDF

Abstract

Polarization-entangled photon pairs generated from second-order nonlinear optical media have been extensively studied for both fundamental research and potential applications of quantum information. In a spontaneous parametric down-conversion process, quantum entanglement between paired photons, often regarded as 'mysterious,' has been demonstrated for local randomness and nonlocal correlation through polarization-basis projections using linear optics (Phys. Rev. A 60, R773 (1999)). Unlike the conventional particle nature-based perspective, this paper presents a coherence analysis rooted in the wave nature of quantum mechanics to examine these well-established quantum phenomena, incorporating polarization control of the paired photons and their projection measurements. First, we analyze the quantum superposition of photon pairs generated randomly from cross-sandwiched nonlinear media, focusing on local randomness, which depends on the incoherence among measured events. Second, we investigate coincidence detection between paired photons to understand the nonlocal correlation arising from independently controlled remote parameters, resulting in an inseparable product-basis relationship. This coherence-based approach sheds light on a deterministic perspective on quantum features, emphasizing the significance of phase information intrinsic to the wave nature of photons, which is incompatible with the particle nature.

DOI
10.1038/s41598-025-95739-8

Related papers

A coherence method generating macroscopic quantum features using polarization-basis control and its projection measurements of laser light

Byoung Seung HAM

Quantum entanglement between paired photons is the foundation of optical quantum computing, quantum sensing, and quantum networks. Traditionally, quantum information science has focused on the particle nature of photons at the microscopic scale, often neglecting the phase information of single photons, even for the bipartite quantum entanglement. Recently, a coherence-based approach has been explored to understand the so-called quantum mystery of nonlocal intensity fringes emerging from local randomness. Here, a pure coherence method is presented to create macroscopic quantum features using conventional laser light via linear optics-based measurement modifications. To achieve this, a polarization-basis control of the laser light is conducted to generate indistinguishable characteristics between orthogonally polarized light pairs. Using projection measurements of the polarization-controlled light pairs, we derive coherence solutions of local randomness and nonlocal correlations between independently controlled local parameters, where a fixed relative phase relationship between paired lights is an essential condition to determine the corresponding Bell states.

arXiv:2410.01198•Oct 2, 2024•0 citations

Wave nature-based nonlocal correlation via projection measurements between space-like separated interferometric systems

Byoung Seung HAM

Indistinguishability in quantum mechanics is an essential concept to understanding mysterious quantum features such as self-interference of a single photon and two-photon nonlocal correlation. Delayed-choice experiments are for the cause-effect violation via post-measurements of photons in an interferometric system. Recently, a macroscopic version of the delayed-choice experiments has been demonstrated using the classical means of Poisson distributed photons in a noninterfering Mach-Zehnder interferometer (NMZI). Here, a coherence version of the nonlocal correlation is presented using the wave nature of photons in space-like separated orthogonally polarized NMZIs. For this, polarization-basis projections of the pair of NMZI output photons onto a set of polarizers are measured coincidently, where each output photon comprises orthogonal polarization bases. Because of the coherence feature of the output photons via coincidence detection, a phase sensitive nonlocal correlation is achieved. As a result, indistinguishability limited to a single or entangled photon pairs needs to be reconsidered with basis (polarization) randomness for the nonlocal correlation.

arXiv:2202.11321•Feb 23, 2022•0 citations

Coherence interpretation of the noninterfering Sagnac-based quantum correlation

Byoung Seung HAM

Bell inequality violation is a quantitative measurement tool for quantum entanglement. Quantum entanglement is the heart of quantum information science, in which the resulting nonlocal correlation between remotely separated photons shows a unique property of quantum mechanics. Here, the role of coincidence detection is coherently investigated for the nonlocal correlation in a simple polarization-basis selective non-interferometric system using entangled photon pairs (Phys. Rev. A 73, 012316 (2006)). The resulting nonlocal quantum feature between two independent local polarizers is coherently derived for the joint-parameter relation of the inseparable intensity product. The resulting coherence solution based on the wave nature of quantum mechanics is thus understood as a deterministic process via coincidence detection-caused measurement modification.

arXiv:2206.05358•Jun 10, 2022•0 citations

Coherently induced quantum correlation in a delayed-choice scheme

Byoung Seung HAM

Quantum entanglement is known as a unique quantum feature that cannot be obtained by classical physics. Over the last several decades, however, such an understanding on quantum entanglement might have confined us in a limited world of weird quantum mechanics. Unlike a single photon, a definite phase relation between paired photons is the key to understanding quantum features. Recently, an intuitive approach to the otherwise mysterious quantum features has emerged and shined a light on coherence manipulations of product-basis superposition via selective measurements. Here, a coherence manipulation is presented to excite polarization-path correlation using Poisson-distributed coherent photons for a classically excited joint-phase relation of independent local parameters. For this, linear optics is used for the preparation of the polarization-basis randomness, and a gated heterodyne detection technique is adopted for the selective measurement of polarization bases. As a result, the nonlocal quantum feature is now coherently understood in a deterministic way.

arXiv:2303.15052•Mar 27, 2023•0 citations

Coherently controlled quantum features in a coupled interferometric scheme

Byoung Seung HAM

Over the last several decades, entangled photon pairs generated by spontaneous parametric down conversion processes in both second-order and third-order nonlinear optical materials have been intensively studied for various quantum features such as Bell inequality violation and anticorrelation. In an interferometric scheme, anticorrelation results from photon bunching based on randomness when entangled photon pairs coincidently impinge on a beam splitter. Compared with post-measurement-based probabilistic confirmation, a coherence version has been recently proposed using the wave nature of photons. Here, the origin of quantum features in a coupled interferometric scheme is investigated using pure coherence optics. In addition, a deterministic method of entangled photon-pair generation is proposed for on-demand coherence control of quantum processing.

arXiv:2102.09189•Scientific Reports•May 27, 2021•9 citations

Experimental demonstrations for randomness-based macroscopic Franson-type nonlocal correlation using coherently coupled photons

S. Kim, Byoung Seung HAM

Franson-type nonlocal quantum correlation based on the particle nature of quantum mechanics has been intensively studied for both fundamental physics and potential applications of quantum key distribution between remotely separated parties over the last several decades. Recently, a coherence theory of deterministic quantum features has been applied for Franson-type nonlocal correlation [arXiv:2102.06463] to understand its quantumness in a purely classical manner, where the resulting features are deterministic and macroscopic. Here, nearly sub-Poisson distributed coherent photon pairs obtained from an attenuated laser are used for the experimental demonstrations of the coherence Franson-type nonlocal correlation. As an essential requirement of quantum mechanics, quantum superposition is macroscopically provided using polarization basis-randomness via a half-wave plate, satisfying fairness compared with the original scheme based on phase bases. The observed coherence quantum feature of the modified Franson correlation successfully demonstrates the proposed wave nature of quantum mechanics, where the unveiled nonlocal correlation is relied on a definite phase relation between the paired coherent photons.

arXiv:2107.00302•Jul 1, 2021•0 citations
Polarization-entangled photon pairs generated from second-order nonlinear optical media have been extensively studied for both fundamental research and potential applications of quantum information. In a spontaneous parametric down-conversion process, quantum entanglement between paired photons, often regarded as 'mysterious,' has been demonstrated for local randomness and nonlocal correlation through polarization-basis projections using linear optics (Phys. Rev. A 60, R773 (1999)). Unlike the conventional particle nature-based perspective, this paper presents a coherence analysis rooted in the wave nature of quantum mechanics to examine these well-established quantum phenomena, incorporating polarization control of the paired photons and their projection measurements. First, we analyze the quantum superposition of photon pairs generated randomly from cross-sandwiched nonlinear media, focusing on local randomness, which depends on the incoherence among measured events. Second, we investigate coincidence detection between paired photons to understand the nonlocal correlation arising from independently controlled remote parameters, resulting in an inseparable product-basis relationship. This coherence-based approach sheds light on a deterministic perspective on quantum features, emphasizing the significance of phase information intrinsic to the wave nature of photons, which is incompatible with the particle nature.
Quantum entanglement between paired photons is the foundation of optical quantum computing, quantum sensing, and quantum networks. Traditionally, quantum information science has focused on the particle nature of photons at the microscopic scale, often neglecting the phase information of single photons, even for the bipartite quantum entanglement. Recently, a coherence-based approach has been explored to understand the so-called quantum mystery of nonlocal intensity fringes emerging from local randomness. Here, a pure coherence method is presented to create macroscopic quantum features using conventional laser light via linear optics-based measurement modifications. To achieve this, a polarization-basis control of the laser light is conducted to generate indistinguishable characteristics between orthogonally polarized light pairs. Using projection measurements of the polarization-controlled light pairs, we derive coherence solutions of local randomness and nonlocal correlations between independently controlled local parameters, where a fixed relative phase relationship between paired lights is an essential condition to determine the corresponding Bell states.
Indistinguishability in quantum mechanics is an essential concept to understanding mysterious quantum features such as self-interference of a single photon and two-photon nonlocal correlation. Delayed-choice experiments are for the cause-effect violation via post-measurements of photons in an interferometric system. Recently, a macroscopic version of the delayed-choice experiments has been demonstrated using the classical means of Poisson distributed photons in a noninterfering Mach-Zehnder interferometer (NMZI). Here, a coherence version of the nonlocal correlation is presented using the wave nature of photons in space-like separated orthogonally polarized NMZIs. For this, polarization-basis projections of the pair of NMZI output photons onto a set of polarizers are measured coincidently, where each output photon comprises orthogonal polarization bases. Because of the coherence feature of the output photons via coincidence detection, a phase sensitive nonlocal correlation is achieved. As a result, indistinguishability limited to a single or entangled photon pairs needs to be reconsidered with basis (polarization) randomness for the nonlocal correlation.
Bell inequality violation is a quantitative measurement tool for quantum entanglement. Quantum entanglement is the heart of quantum information science, in which the resulting nonlocal correlation between remotely separated photons shows a unique property of quantum mechanics. Here, the role of coincidence detection is coherently investigated for the nonlocal correlation in a simple polarization-basis selective non-interferometric system using entangled photon pairs (Phys. Rev. A 73, 012316 (2006)). The resulting nonlocal quantum feature between two independent local polarizers is coherently derived for the joint-parameter relation of the inseparable intensity product. The resulting coherence solution based on the wave nature of quantum mechanics is thus understood as a deterministic process via coincidence detection-caused measurement modification.
Quantum entanglement is known as a unique quantum feature that cannot be obtained by classical physics. Over the last several decades, however, such an understanding on quantum entanglement might have confined us in a limited world of weird quantum mechanics. Unlike a single photon, a definite phase relation between paired photons is the key to understanding quantum features. Recently, an intuitive approach to the otherwise mysterious quantum features has emerged and shined a light on coherence manipulations of product-basis superposition via selective measurements. Here, a coherence manipulation is presented to excite polarization-path correlation using Poisson-distributed coherent photons for a classically excited joint-phase relation of independent local parameters. For this, linear optics is used for the preparation of the polarization-basis randomness, and a gated heterodyne detection technique is adopted for the selective measurement of polarization bases. As a result, the nonlocal quantum feature is now coherently understood in a deterministic way.
Over the last several decades, entangled photon pairs generated by spontaneous parametric down conversion processes in both second-order and third-order nonlinear optical materials have been intensively studied for various quantum features such as Bell inequality violation and anticorrelation. In an interferometric scheme, anticorrelation results from photon bunching based on randomness when entangled photon pairs coincidently impinge on a beam splitter. Compared with post-measurement-based probabilistic confirmation, a coherence version has been recently proposed using the wave nature of photons. Here, the origin of quantum features in a coupled interferometric scheme is investigated using pure coherence optics. In addition, a deterministic method of entangled photon-pair generation is proposed for on-demand coherence control of quantum processing.
Franson-type nonlocal quantum correlation based on the particle nature of quantum mechanics has been intensively studied for both fundamental physics and potential applications of quantum key distribution between remotely separated parties over the last several decades. Recently, a coherence theory of deterministic quantum features has been applied for Franson-type nonlocal correlation [arXiv:2102.06463] to understand its quantumness in a purely classical manner, where the resulting features are deterministic and macroscopic. Here, nearly sub-Poisson distributed coherent photon pairs obtained from an attenuated laser are used for the experimental demonstrations of the coherence Franson-type nonlocal correlation. As an essential requirement of quantum mechanics, quantum superposition is macroscopically provided using polarization basis-randomness via a half-wave plate, satisfying fairness compared with the original scheme based on phase bases. The observed coherence quantum feature of the modified Franson correlation successfully demonstrates the proposed wave nature of quantum mechanics, where the unveiled nonlocal correlation is relied on a definite phase relation between the paired coherent photons.