scholarly journals Quantum Correlations

2021 ◽  
pp. 223-292
Author(s):  
Nuel Belnap ◽  
Thomas MÜller ◽  
Tomasz Placek
Keyword(s):  
Quantum Correlations ◽  
Quantum Mechanical ◽  
Important Distinction ◽  
Extended Structure

This chapter analyzes the phenomenon of quantum mechanical correlations using the BST notions of transitions, propensities, and funny business. It considers two ways of understanding such correlations: First, as modal correlations (exhibited, e.g., in the GHZ setup) and, second, as probabilistic correlations (exhibited, e.g., in the Bell-Aspect setup). Having introduced the notion of structure extensions, it asks if it is possible to extend an initial BST structure harboring correlations (modal or probabilistic) in such a way that the resulting extended structure harbors no such correlations. An important distinction, rigorously stated in BST, is that between agents-induced indeterminism and Nature-induced indeterminism. A main result concerning structure extensions is that in the mentioned cases, the procedure is not possible unless the extended structure violates the initially given division between cases of agents-induced indeterminism and cases of Nature-induced indeterminism.

MONOGAMY OF ENTANGLEMENT, N-REPRESENTABILITY PROBLEMS AND GROUND STATES

2012 ◽  
Vol 26 (27n28) ◽  
pp. 1243014
Author(s):  
TZU-CHIEH WEI
Keyword(s):  
Mechanical Property ◽  
Ground State ◽  
State Energy ◽  
Mean Field ◽  
System Size ◽  
Quantum Correlations ◽  
Quantum Mechanical ◽  
Ground State Wavefunction ◽  
Strong Competition ◽  
Quantum Mechanical Property

Monogamy of entanglement is a quantum mechanical property that limits quantum correlations shared among many parties. In an example strongly interacting spin system we examine approaches for approximating the ground state energy both from above and below by mean-field and N-representability methods, respectively. Due to strong competition among the terms in the Hamiltonian, the resulting ground-state wavefunction, although is entangled, does not possess entanglement that is proportional to the system size, thus obeying the monogamy of entanglement.

scholarly journals CTC assisted PR box type correlation can lead to signaling

2014 ◽  
Vol 14 (13&14) ◽  
pp. 1251-1260
Author(s):  
Indranil Chakrabarty ◽  
Tanumoy Pramanik ◽  
Arun K Pati ◽  
Pankaj Agrawal
Keyword(s):  
Quantum Correlations ◽  
Quantum Mechanical ◽  
Local Correlations ◽  
No Signaling ◽  
Non Local

It is known that there exist non-local correlations that respect no-signaling criterion, but violate Bell-type inequalities more than quantum-mechanical correlations. Such super quantum correlations were introduced as the Popescu-Rohrlich (PR) box. We consider such non-local boxes with two/three inputs and two/three outputs. We show that these super quantum correlations can lead to signaling when at least one of the input bit has access to a word line along a closed time-like curve.

QUANTUM SIZE EFFECTS IN SUPERCONDUCTING JUNCTIONS WITH A FERROMAGNETIC INTERLAYER

2011 ◽  
Vol 09 (supp01) ◽  
pp. 301-307 ◽  
Author(s):  
M. BELOGOLOVSKII ◽  
N. DE LEO ◽  
M. FRETTO ◽  
V. LACQUANITI
Keyword(s):  
Ballistic Transport ◽  
Quantum Correlations ◽  
Quantum Mechanical ◽  
Tunneling Conductance ◽  
Double Peak ◽  
Double Peak Structure ◽  
Clean Limit ◽  
Peak Structure ◽  
Quantum Size ◽  
Sensitive Tool

Motivated by a recent experiment evidencing an unusual double-peak structure in tunneling conductance spectra of a nano-sized ferromagnet — superconductor bilayer, we propose a clean-limit scattering-like model for a quasi-ballistic transport in superconducting heterostructures with conducting ferromagnetic films. The model also includes an effect of charge interactions with an environment which partially degrade quantum correlations in the system. Our numerical simulations show that (i) the observed feature arises from a quantum-mechanical geometrical size effect and (ii) such measurements can serve as a sensitive tool for controlling quantum-mechanical phenomena in the studied junctions.

Difference mode EXELFS with parallel-detection EELS

1992 ◽  
Vol 50 (2) ◽  
pp. 1262-1263
Author(s):  
Michael K. Kundmann ◽  
Ondrej L. Krivanek
Keyword(s):  
Edge Detection ◽  
Important Distinction ◽  
Edge Structure ◽  
Parallel Detection ◽  
Gain Variation ◽  
Ideal Solutions ◽  
Detector Cell ◽  
The Difference ◽  
Elemental Detection ◽  
Partial Correction

Parallel detection has greatly improved the elemental detection sensitivities attainable with EELS. An important element of this advance has been the development of differencing techniques which circumvent limitations imposed by the channel-to-channel gain variation of parallel detectors. The gain variation problem is particularly severe for detection of the subtle post-threshold structure comprising the EXELFS signal. Although correction techniques such as gain averaging or normalization can yield useful EXELFS signals, these are not ideal solutions. The former is a partial throwback to serial detection and the latter can only achieve partial correction because of detector cell inhomogeneities. We consider here the feasibility of using the difference method to efficiently and accurately measure the EXELFS signal.An important distinction between the edge-detection and EXELFS cases lies in the energy-space periodicities which comprise the two signals. Edge detection involves the near-edge structure and its well-defined, shortperiod (5-10 eV) oscillations. On the other hand, EXELFS has continuously changing long-period oscillations (∼10-100 eV).

A trace of equity in Utopia? On Raphael's reformulation of classical equity

Moreana ◽  
2017 ◽  
Vol 54 (Number 207) (1) ◽  
pp. 19-35
Author(s):  
Louis W. Karlin ◽  
Jordan D. Teti
Keyword(s):  
Important Distinction ◽  
Written Law ◽  
Aristotle's Ethics

“Equity,” a fertile concept for understanding justice in More's time, has its origins in Greek and Roman philosophy. As the putative emissary of Greek (and Ciceronian) philosophy in More's Utopia, it is thus fitting that Raphael Hythloday expressly acknowledges classical sources in his references to equity, such as in his allusion to the “leaden rule” of Aristotle and his paraphrase of Cicero's famous epigram, “summum ius, summa iniuria.” In substance, however, Raphael's understanding of equity differs from that of Plato, Aristotle, and Cicero. For example, while classical thinkers sought flexibility in the application of written law so as to accord with a higher justice (as in the “leaden rule”), Raphael rejects such impure flexibility. Also, Utopia, itself, a land with few laws and fewer lawyers, lacks equity as it was traditionally understood—that is, as a justice-facilitating corrective to the imprecision of written law. Nevertheless, Raphael emotionally concludes Book Two by apparently praising the “fairness” (aequitas) of Utopia. Despite his appeals to equity, Raphael actually appears to be an inequitable man in the action of the dialogue, with his brash monologues, tendentious citations of the Gospel, and dubious references to equity, itself. By contrast, Cardinal Morton and Morus embody the traits of the “equitable man,” a figure with a key role in promoting justice in Aristotle's Ethics and Rhetoric and in bringing about the best regime in Plato's Laws and Republic. This irony in Utopia helps readers appreciate the fruits and risks of incorporating philosophy into politics, especially as it relates to clamoring for reform. We see the important distinction between impassioned partisans of philosophy (such as Raphael) and the enlightened gentleness of men like Morton and Morus.

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