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Full-Text Articles in Physics
Entangled Photon Anti-Correlations Are Evident From Classical Electromagnetism, Ken Wharton, Emily Adlam
Entangled Photon Anti-Correlations Are Evident From Classical Electromagnetism, Ken Wharton, Emily Adlam
Mathematics, Physics, and Computer Science Faculty Articles and Research
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 that these very anti-correlations are also evident when the input to the same experiment is analyzed via classical electromagnetic theory. Demonstrating this quantum–classical connection for arbitrary two-photon states and analyzing why it is successful motivates alternative perspectives concerning entanglement, the path integral, and other topics in quantum foundations.
Quark And Gluon Entanglement In The Proton On The Light Cone At Intermediate X, Adrian Dumitru, Eric Kolbusz
Quark And Gluon Entanglement In The Proton On The Light Cone At Intermediate X, Adrian Dumitru, Eric Kolbusz
Publications and Research
In QCD with $N_c$ colors the antisymmetric valence quark color space singlet state $\sim \epsilon_{i_1\cdots i_{N_c}} |i_1,\cdots, i_{N_c}\rangle$ of the proton corresponds to the reduced density matrix $\rho_{ij}=(1/N_c) \delta_{ij}$ for a single color degree of freedom. Its degenerate spectrum of eigenvalues, $\lambda_i=1/N_c$, the purity $\tr \rho^2 = 1/N_c$, and the von Neumann entropy $S_\mathrm{vN}=\log(N_c)$ all indicate maximal entanglement of color. On the other hand, for $N_c\to\infty$ the spatial wave function of the proton factorizes into valence quark wave functions determined by a mean field [E. Witten, Nucl. Phys. B160, 57 (1979)] where there is no entanglement of spatial degrees of …
Extractable Entanglement From A Euclidean Hourglass, Takanori Anegawa, Norihiro Iizuka, Daniel Kabat
Extractable Entanglement From A Euclidean Hourglass, Takanori Anegawa, Norihiro Iizuka, Daniel Kabat
Publications and Research
We previously proposed that entanglement across a planar surface can be obtained from the partition function on a Euclidean hourglass geometry. Here we extend the prescription to spherical entangling surfaces in conformal field theory. We use the prescription to evaluate log terms in the entropy of a conformal field theory in two dimensions, a conformally coupled scalar in four dimensions, and a Maxwell field in four dimensions. For Maxwell we reproduce the extractable entropy obtained by Soni and Trivedi. We take this as evidence that the hourglass prescription provides a Euclidean technique for evaluating extractable entropy in quantum field theory.
Interaction-Free Effects Between Distant Atoms, Yakir Aharonov, Eliahu Cohen, Avshalom C. Elitzur, Lee Smolin
Interaction-Free Effects Between Distant Atoms, Yakir Aharonov, Eliahu Cohen, Avshalom C. Elitzur, Lee Smolin
Mathematics, Physics, and Computer Science Faculty Articles and Research
A Gedanken experiment is presented where an excited and a ground-state atom are positioned such that, within the former’s half-life time, they exchange a photonwith 50% probability.Ameasurement of their energy statewill therefore indicate in 50% of the cases that no photon was exchanged. Yet other measurements would reveal that, by the mere possibility of exchange, the two atoms have become entangled. Consequently, the “no exchange” result, apparently precluding entanglement, is non-locally established between the atoms by this very entanglement. This quantum-mechanical version of the ancient Liar Paradox can be realized with already existing transmission schemes, with the addition of Bell’s …
Quantum Violation Of The Pigeonhole Principle And The Nature Of Quantum Correlations, Yakir Aharonov, Fabrizio Colombo, S. Popescu, Irene Sabadini, Daniele C. Struppa, Jeff Tollaksen
Quantum Violation Of The Pigeonhole Principle And The Nature Of Quantum Correlations, Yakir Aharonov, Fabrizio Colombo, S. Popescu, Irene Sabadini, Daniele C. Struppa, Jeff Tollaksen
Mathematics, Physics, and Computer Science Faculty Articles and Research
The pigeonhole principle: "If you put three pigeons in two pigeonholes at least two of the pigeons end up in the same hole" is an obvious yet fundamental principle of Nature as it captures the very essence of counting. Here however we show that in quantum mechanics this is not true! We find instances when three quantum particles are put in two boxes, yet no two particles are in the same box. Furthermore, we show that the above "quantum pigeonhole principle" is only one of a host of related quantum effects, and points to a very interesting structure of quantum …
Everything Is Entangled, Roman V. Buniy, Stephen D. H. Hsu
Everything Is Entangled, Roman V. Buniy, Stephen D. H. Hsu
Mathematics, Physics, and Computer Science Faculty Articles and Research
We show that big bang cosmology implies a high degree of entanglement of particles in the universe. In fact, a typical particle is entangled with many particles far outside our horizon. However, the entanglement is spread nearly uniformly so that two randomly chosen particles are unlikely to be directly entangled with each other - the reduced density matrix describing any pair is likely to be separable.