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Related papers: Quantum State of Entangled Photon Pairs

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EPR showed that two particles emitted from a source can be entangled by a shared wavefunction where two non-commuting observables (position, momentum) can be simultaneously real, leading to a contradiction with quantum mechanics (two…

Quantum Physics · Physics 2026-03-12 Mafiz Uddin

Entanglement is an extraordinary feature of quantum mechanics. Sources of entangled optical photons were essential to test the foundations of quantum physics through violations of Bell's inequalities. More recently, entangled many-body…

We show that for a class of quantum light spectroscopy (QLS) experiments using n = 0,1,2,$\cdots$ classical light pulses and an entangled photon pair (a biphoton state) where one photon acts as a reference without interacting with the…

Quantum Physics · Physics 2024-02-26 Liwen Ko , Robert L. Cook , K. Birgitta Whaley

Entanglement is the central resource of quantum information processing and the precise characterization of entangled states is a crucial issue for the development of quantum technologies. This leads to the necessity of a precise,…

Bell state measurements, in which two quantum bits are projected onto a maximally entangled state, are an essential component of quantum information science. We propose and experimentally demonstrate the projection of two quantum systems…

Quantum Physics · Physics 2011-03-31 A. Halevy , E. Megidish , T. Shacham , L. Dovrat , H. S. Eisenberg

By limiting the resolution of quantum measurements, the measurement induced changes of the quantum state can be reduced, permitting subsequent measurements of variables that do not commute with the initially measured property. It is then…

Quantum Physics · Physics 2009-11-06 Holger F. Hofmann

We propose a setup that transforms a photon pair in arbitrary rank-four mixed state, which could also be unknown, to a Bell state. The setup involves two linear optical circuits processing the individual photons and a parity gate working…

Quantum Physics · Physics 2009-12-23 Bing He , Yuhang Ren , Janos A. Bergou

Entanglement and Bell nonlocality are known to be inequivalent: there exist entangled states that admit a local hidden-variable model for all local measurements. Here we show that this gap disappears in a minimal broadcast extension of the…

Quantum Physics · Physics 2025-12-18 Pavel Sekatski , Jef Pauwels

Bell's states are among the most useful in quantum computing. These state are an orthonormal base of entagled states with two qubits. We propose alternative bases of entangled states. Some of these states depend on a continuous parameter.…

Quantum Physics · Physics 2025-05-28 Juan M. Romero , Emiliano Montoya-Gonzalez , Oscar Velazquez-Alvarado

It has been claimed that ``the use of entangled photons in an imaging system can exhibit effects that cannot be mimicked by any other two-photon source, whatever strength of the correlations between the two photons'' [A. F. Abouraddy, B. E.…

Quantum Physics · Physics 2007-05-23 Gunnar Bjork , Jonas Soderholm , Luis L. Sanchez-Soto

The cascaded decay in a four-level quantum emitter is a well established mechanism to generate polarization entangled photon pairs, the building blocks of many applications in quantum technologies. The four most prominent maximally…

We implement experimentally a deterministic method to prepare and measure so called single-photon two-qubit entangled states or single-photon Bell-states, in which the polarization and the spatial modes of a single-photon each represent a…

Quantum Physics · Physics 2009-11-10 Yoon-Ho Kim

We present a protocol for probing the state of a quantum system by its resonant coupling and entanglement with a meter system. By continuous measurement of a time evolving meter observable, we infer the evolution of the entangled systems…

Quantum Physics · Physics 2022-10-05 A. L. Andersen , K. Mølmer

Frequency non-degenerate entangled photon pairs have been employed in quantum communication, imaging, and sensing. To characterize quantum entangled state with long-wavelength (infrared, IR or even terahertz, THz) photon, one needs to…

Quantum Physics · Physics 2021-01-27 Yiquan Yang , Peiyu Zhang , Xiao-Song Ma

We propose a review of recent developments on entanglement and non-classical effects in collective two-atom systems and present a uniform physical picture of the many predicted phenomena. The collective effects have brought into sharp focus…

Quantum Physics · Physics 2009-11-10 Z. Ficek , R. Tanas

We show how entangled qubits can be encoded as entangled coherent states of two-dimensional centre-of-mass vibrational motion for two ions in an ion trap. The entangled qubit state is equivalent to the canonical Bell state, and we introduce…

Quantum Physics · Physics 2009-10-31 W. J. Munro , G. J. Milburn , B. C. Sanders

Simulation tasks are insightful tools to compare information-theoretic resources. Considering a generalization of usual Bell scenarios where external quantum inputs are provided to the parties, we show that any entangled quantum state…

Quantum Physics · Physics 2013-06-06 Denis Rosset , Cyril Branciard , Nicolas Gisin , Yeong-Cherng Liang

We investigate the evolution of quantum correlations over the lifetime of a multi-photon state. Measurements reveal time-dependent oscillations of the entanglement fidelity for photon pairs created by a single semiconductor quantum dot. The…

For any experiment with two entangled photons, some joint measurement outcomes can have zero probability for a precise choice of basis. These perfect anti-correlations would seem to be a purely quantum phenomenon. It is therefore surprising…

Quantum Physics · Physics 2022-08-12 Ken Wharton , Emily Adlam

Non-linear properties of quantum states, such as entropy or entanglement, quantify important physical resources and are frequently used in quantum information science. They are usually calculated from a full description of a quantum state,…