Weekly Papers on Quantum Foundations (51)

This is a list of this week’s papers on quantum foundations published in various journals or uploaded to preprint servers such as arxiv.org and PhilSci Archive.

Fundamental constraints on two-time physics. (arXiv:1512.05345v1 [quant-ph])

hep-th updates on arXiv.org

on 2015-12-19 7:40am GMT

Authors: E. PicenoA. RosadoE. Sadurní

We show that generalizations of classical and quantum dynamics with two times lead to fundamentally constrained evolution. At the level of classical physics, Newton’s second law is extended and exactly integrated in $1+2$ dimensional space, leading to effective single-time evolution for any initial condition. In the domain of quantum mechanics, we follow strictly the hypothesis of probability conservation by extending the Heisenberg picture to unitary evolution with two times. As a result, the observability of two temporal axes is constrained by a generalized uncertainty relation involving level spacings, total duration of the effect and Planck’s constant.

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Any quantum contextuality can be tested in a simple experiment. (arXiv:1512.05370v1 [quant-ph])

quant-ph updates on arXiv.org

on 2015-12-19 7:40am GMT

Authors: Adán Cabello

Contextuality provides a unifying paradigm for nonclassical aspects of quantum probabilities and resources of quantum information. Unfortunately, most forms of quantum contextuality remain experimentally unexplored due to the difficulty of performing sequences of projective measurements on individual quantum systems. Here we show that two-point correlations between dichotomic compatible observables are sufficient to reveal any form of contextuality. This allows us to design simple experiments that are more robust against imperfections and easier to analyze, thus opening the door for observing interesting forms of contextuality, including those requiring quantum systems of high dimensions. In addition, this result allows us to connect contextuality to communication complexity scenarios and reformulate a recent result relating contextuality and quantum computation.

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Reality of the quantum state: A new proof in terms of protective measurements

PhilSci-Archive: No conditions. Results ordered -Date Deposited.

on 2015-12-18 9:52pm GMT

Gao, Shan (2015) Reality of the quantum state: A new proof in terms of protective measurements. [Preprint]

Less Decoherence and More Coherence in Quantum Gravity, Inflationary Cosmology and Elsewhere

PhilSci-Archive: No conditions. Results ordered -Date Deposited.

on 2015-12-17 6:11pm GMT

Okon, Elias and Sudarsky, Daniel (2015) Less Decoherence and More Coherence in Quantum Gravity, Inflationary Cosmology and Elsewhere. [Preprint]

Non-Newtonian Aspects of Artificial Intelligence

Latest Results for Foundations of Physics

on 2015-12-17 12:00am GMT

Abstract

The challenge of this work is to connect physics with the concept of intelligence. By intelligence we understand a capability to move from disorder to order without external resources, i.e., in violation of the second law of thermodynamics. The objective is to find such a mathematical object described by ODE that possesses such a capability. The proposed approach is based upon modification of the Madelung version of the Schrodinger equation by replacing the force following from quantum potential with non-conservative forces that link to the concept of information. A mathematical formalism suggests that a hypothetical intelligent particle, besides the capability to move against the second law of thermodynamics, acquires such properties like self-image, self-awareness, self-supervision, etc. that are typical for Livings. However since this particle being a quantum-classical hybrid acquires non-Newtonian and non-quantum properties, it does not belong to the physics matter as we know it: the modern physics should be complemented with the concept of the information force that represents a bridge to intelligent particle. As a follow-up of the proposed concept, the following question is addressed: can artificial intelligence (AI) system composed only of physical components compete with a human? The answer is proven to be negative if the AI system is based only on simulations, and positive if digital devices are included. It has been demonstrated that there exists such a quantum neural net that performs simulations combined with digital punctuations. The universality of this quantum-classical hybrid is in capability to violate the second law of thermodynamics by moving from disorder to order without external resources. This advanced capability is illustrated by examples. In conclusion, a mathematical machinery of the perception that is the fundamental part of a cognition process as well as intelligence is introduced and discussed.

Significant-Loophole-Free Test of Bell’s Theorem with Entangled Photons

PRL Editors’ Suggestions

on 2015-12-16 3:00pm GMT

Author(s): Marissa Giustina, Marijn A. M. Versteegh, Sören Wengerowsky, Johannes Handsteiner, Armin Hochrainer, Kevin Phelan, Fabian Steinlechner, Johannes Kofler, Jan-Åke Larsson, Carlos Abellán, Waldimar Amaya, Valerio Pruneri, Morgan W. Mitchell, Jörn Beyer, Thomas Gerrits, Adriana E. Lita, Lynden K. Shalm, Sae Woo Nam, Thomas Scheidl, Rupert Ursin, Bernhard Wittmann, and Anton Zeilinger

By closing two loopholes at once, three experimental tests of Bell’s inequalities remove the last doubts that we should renounce local realism. They also open the door to new quantum information technologies.

[Phys. Rev. Lett. 115, 250401] Published Wed Dec 16, 2015

Quantum theory allows for absolute maximal contextuality

PRA: Fundamental concepts

on 2015-12-16 3:00pm GMT

Author(s): Barbara Amaral, Marcelo Terra Cunha, and Adán Cabello

Contextuality is believed to be a fundamental property of quantum theory. On investigating how large it can be, instances are shown wherein quantum theory achieves the maximum conceivable value of a certain contextuality quantifier.

[Phys. Rev. A 92, 062125] Published Wed Dec 16, 2015

Strong Loophole-Free Test of Local Realism

PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

on 2015-12-16 3:00pm GMT

Author(s): Lynden K. Shalm et al.

By closing two loopholes at once, three experimental tests of Bell’s inequalities remove the last doubts that we should renounce local realism. They also open the door to new quantum information technologies.

[Phys. Rev. Lett. 115, 250402] Published Wed Dec 16, 2015

Quantum physics: Entanglement beyond identical ions

Nature Physical Sciences Research

on 2015-12-16 12:00am GMT

Control of quantum particles has been extended to enable different types of ion to be entangled — correlated in a non-classical way. This opens up opportunities for the development of new quantum technologies. See Letters p.380 & p.384

Nature 528 337 doi: 10.1038/528337a

Weak values obtained in matter-wave interferometry

PRA: Fundamental concepts

on 2015-12-14 3:00pm GMT

Author(s): Stephan Sponar, Tobias Denkmayr, Hermann Geppert, Hartmut Lemmel, Alexandre Matzkin, Jeff Tollaksen, and Yuji Hasegawa

Weak values, introduced more than 25 years ago, underwent a metamorphosis from a theoretical curiosity to a powerful resource in photonics for exploring foundations of quantum mechanics, as well as a practical laboratory tool. Due to the tiny coherence volume of particles used in matter-wave optics,…

 

[Phys. Rev. A 92, 062121] Published Mon Dec 14, 2015

What does it feel like to be in a quantum superposition?

PhilSci-Archive: No conditions. Results ordered -Date Deposited.

on 2015-12-13 6:17pm GMT

Gao, Shan (2015) What does it feel like to be in a quantum superposition? [Preprint]

 

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