Investigation of the collapse of quantum states using entangled photons

Nonlinear 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, even though they depend only on a small number of parameters that specify the state. Here we extract a nonlocal and a nonlinear quantity, namely the Renyi entropy, from local measurements on two pairs of polarization entangled photons. We also introduce a "phase marking" technique which allows to select uncorrupted outcomes even with nondeterministic sources of entangled photons. We use our experimental data to demonstrate the violation of entropic inequalities. They are examples of a nonlinear entanglement witness and their power exceeds all linear tests for quantum entanglement based on all possible Bell-CHSH inequalities.

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Quantum Rayleigh Annihilation of Entangled Photons

10.20944/preprints201807.0280.v1 ◽

2018 ◽

Author(s):

Andre Vatarescu

Keyword(s):

Physical Reality ◽

Quantum States ◽

Entangled States ◽

Entangled Photons ◽

Dielectric Media ◽

Quantum Phenomenon ◽

Quantum Non Locality ◽

Linearly Polarized ◽

Photonic States ◽

Non Locality

The interpretation of published experimental results intended to prove the existence of a quantum phenomenon of non-locality involving photonic entangled states did not take into consideration the existence of the quantum Rayleigh conversion of photons in dielectric media. This phenomenon leads to the existence of high levels of correlations between two independent photonic and linearly polarized quantum states generated after the entangled photons have been absorbed through the quantum Rayleigh conversion. Both pure and mixed individual states of polarization result in expressions normally associated with entangled photonic states, providing support for the view that the physical reality of quantum non-locality is highly questionable.

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Quantum Rayleigh Annihilation of Entangled Photons

10.20944/preprints201807.0280.v2 ◽

2018 ◽

Author(s):

Andre Vatarescu

Keyword(s):

Physical Reality ◽

Quantum States ◽

Entangled States ◽

Entangled Photons ◽

Dielectric Media ◽

Quantum Phenomenon ◽

Quantum Non Locality ◽

Linearly Polarized ◽

Photonic States ◽

Non Locality

The interpretation of published experimental results intended to prove the existence of a quantum phenomenon of non-locality involving photonic entangled states did not take into consideration the existence of the quantum Rayleigh conversion of photons in dielectric media. This phenomenon leads to the existence of high levels of correlations between two independent photonic and linearly polarized quantum states generated after the entangled photons have been absorbed through the quantum Rayleigh conversion. Both pure and mixed individual states of polarization result in expressions normally associated with entangled photonic states, providing support for the view that the physical reality of quantum non-locality is highly questionable.

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Entanglement

Quantum 20/20 ◽

10.1093/oso/9780198808350.003.0009 ◽

2019 ◽

pp. 151-162

Author(s):

Ian R. Kenyon

Keyword(s):

Quantum States ◽

Entangled States ◽

Entangled State ◽

Entangled Photons ◽

Photon State ◽

Full Knowledge ◽

Quantum Entangled States ◽

The Individual ◽

Down Conversion ◽

Individual Particles

The distiction between classical product states and quantum entangled states is disclosed with examples. Spontaneous parametric down conversion as a source of entangled photons is described. The action of a perfect beam splitter is analysed using creation and annihilation operators. The HOM interferometer is described. Its use in demonstrating the indistinguishability of photons and in measuring bandwidth of sources at the level of femtoseconds is recounted. Two particle entanglement is analysed using the Bloch sphere representation showing how the full knowledge of the entangled state does not fix the state of the individual particles. The four Bell states, eigenstates of two particle entanglement, are introduced. Teleportation of a photon state using entangled photons is described, and an experiment to entangle the quantum states of atoms at space-like separation outlined.

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Hong-Ou-Mandel interferometry and spectroscopy using entangled photons

Communications Physics ◽

10.1038/s42005-021-00542-2 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Konstantin E. Dorfman ◽

Shahaf Asban ◽

Bing Gu ◽

Shaul Mukamel

Keyword(s):

Measurement Accuracy ◽

Quantum States ◽

Photon Statistics ◽

Entangled Photons ◽

Optical Technology ◽

Two Photon ◽

Enhanced Resolution ◽

Field Correlation ◽

Interferometric Detection

AbstractOptical interferometry has been a long-standing setup for characterization of quantum states of light. Both linear and the nonlinear interferences can provide information regarding the light statistics and underlying detail of the light-matter interactions. Here we demonstrate how interferometric detection of nonlinear spectroscopic signals may be used to improve the measurement accuracy of matter susceptibilities. Light-matter interactions change the photon statistics of quantum light, which are encoded in the field correlation functions. Application is made to the Hong-Ou-Mandel two-photon interferometer that reveals entanglement-enhanced resolution that can be achieved with existing optical technology.

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