Indeterminacy

2020 ◽  
pp. 172-184
Author(s):  
Alastair Wilson
Keyword(s):  
Quantum Mechanics ◽  
Quantum State ◽  
Modal Realism ◽  
Many Worlds ◽  
Philosophical Literature ◽  
Universal Quantum ◽  
Quantum Indeterminacy

In Everettian quantum mechanics, the universal quantum state is fundamental, non-contingent, and wholly determinate. By contrast, the parallel worlds of diverging EQM, and the contingency constituted by self-location amongst those worlds, are emergent and partly indeterminate. In particular, it is indeterminate both how many worlds there are, and what microscopic qualitative features those worlds have. This chapter discusses various ways to understand indeterminacy in the Everettian multiverse, and argues that the indeterminacies of EQM present no obstacle to the analytic ambitions of quantum modal realism. Everettians can understand quantum indeterminacy using models of indeterminacy that are familiar from the philosophical literature on vagueness.

scholarly journals The Cosmic Void

Non-Being ◽  
2021 ◽  
pp. 115-138
Author(s):  
Eddy Keming Chen
Keyword(s):  
Quantum Mechanics ◽  
Quantum State ◽  
Special Kind ◽  
Many Worlds ◽  
Fundamental Level ◽  
Fundamental Matter ◽  
Standard Picture ◽  
The Many ◽  
The Universe

What exists at the fundamental level of reality? On the standard picture, the fundamental reality contains (among other things) fundamental matter, such as particles, fields, or even the quantum state. Non-fundamental facts are explained by facts about fundamental matter, at least in part. In this paper, I introduce a non-standard picture called the “cosmic void” in which the universe is devoid of any fundamental material ontology. Facts about tables and chairs are recovered from a special kind of laws that satisfy strong determinism. All non-fundamental facts are completely explained by nomic facts. I discuss a concrete example of this picture in a strongly deterministic version of the many-worlds theory of quantum mechanics. I discuss some philosophical and scientific challenges to this view, as well as some connections to ontological nihilism.

scholarly journals The measure problem in no-collapse (many worlds) quantum mechanics

2017 ◽  
Vol 26 (03) ◽  
pp. 1730008 ◽  
Author(s):  
Stephen D. H. Hsu
Keyword(s):  
Wave Function ◽  
Quantum Mechanics ◽  
Probability Measure ◽  
Ab Initio ◽  
Subjective Probability ◽  
State Vector ◽  
A Priori ◽  
Born Rule ◽  
Many Worlds ◽  
Measure Problem

We explain the measure problem (cf. origin of the Born probability rule) in no-collapse quantum mechanics. Everett defined maverick branches of the state vector as those on which the usual Born probability rule fails to hold — these branches exhibit highly improbable behaviors, including possibly the breakdown of decoherence or even the absence of an emergent semi-classical reality. Derivations of the Born rule which originate in decision theory or subjective probability (i.e. the reasoning of individual observers) do not resolve this problem, because they are circular: they assume, a priori, that the observer occupies a non-maverick branch. An ab initio probability measure is sometimes assumed to explain why we do not occupy a maverick branch. This measure is constrained by, e.g. Gleason’s theorem or envariance to be the usual Hilbert measure. However, this ab initio measure ultimately governs the allocation of a self or a consciousness to a particular branch of the wave function, and hence invokes primitives which lie beyond the Everett wave function and beyond what we usually think of as physics. The significance of this leap has been largely overlooked, but requires serious scrutiny.

The implementation of universal quantum memory and gates based on large-scale diamond surface

2016 ◽  
Vol 14 (05) ◽  
pp. 1650026
Author(s):  
Xiao-Ning Qi ◽  
Yong Zhang
Keyword(s):  
Quantum State ◽  
Large Scale ◽  
Quantum Memory ◽  
Quantum Gate ◽  
Nitrogen Vacancy ◽  
Diamond Surface ◽  
Single Qubit ◽  
Model Based ◽  
Universal Quantum ◽  
Jc Model

Nitrogen-vacancy (NV) centers implanted beneath the diamond surface have been demonstrated to be effective in the processing of controlling and reading-out. In this paper, NV center entangled with the fluorine nuclei collective ensemble is simplified to Jaynes–Cummings (JC) model. Based on this system, we discussed the implementation of quantum state storage and single-qubit quantum gate.

No-cloning Theorem and Quantum Copying

2020 ◽  
pp. 172-181
Author(s):  
M. Suhail Zubairy
Keyword(s):  
Quantum Mechanics ◽  
Quantum State ◽  
Uncertainty Relation ◽  
Foundations Of Quantum Mechanics ◽  
Quantum Cloning ◽  
Foundation Of Quantum Mechanics ◽  
Quantum Copying ◽  
Arbitrary Quantum ◽  
Principle Of Complementarity

Heisenberg’s uncertainty relation and Bohr’s principle of complementarity form the foundations of quantum mechanics. If these are violated then the edifice of quantum mechanics can come crashing down. In this chapter, it is shown how cloning or perfect copying of a quantum state can potentially lead to a violation of these sacred principles. A no-cloning theorem is proven showing that the cloning of an arbitrary quantum state is not allowed. The foundation of quantum mechanics is therefore protected. It is also shown how quantum cloning can lead to superluminal communication. It is also discussed that, if making a perfect copy of a quantum state is forbidden, how best a copy of a state can be made.

scholarly journals Twenty Years of Quantum State Teleportation at the Sapienza University in Rome

Entropy ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 768 ◽  
Author(s):  
Francesco De De Martini ◽  
Fabio Sciarrino
Keyword(s):  
Quantum Mechanics ◽  
Quantum Optics ◽  
Quantum State ◽  
Quantum Teleportation ◽  
Feed Forward ◽  
Unknown Quantum State ◽  
University Of Rome ◽  
The University ◽  
First Time

Quantum teleportation is one of the most striking consequence of quantum mechanics and is defined as the transmission and reconstruction of an unknown quantum state over arbitrary distances. This concept was introduced for the first time in 1993 by Charles Bennett and coworkers, it has then been experimentally demonstrated by several groups under different conditions of distance, amount of particles and even with feed forward. After 20 years from its first realization, this contribution reviews the experimental implementations realized at the Quantum Optics Group of the University of Rome La Sapienza.

scholarly journals INDETERMINATEZZA METAFISICA E MECCANICA QUANTISTICA

2019 ◽  
Author(s):  
Claudio Calosi
Keyword(s):  
Quantum Mechanics ◽  
Quantum Systems ◽  
Metaphysical Indeterminacy ◽  
Quantum Indeterminacy

The paper argues that quantum mechanics provide examples of genuine metaphysical indeterminacy that cannot be accounted for in purely modal terms. The best account of quantum indeterminacy has it that quantum systems have determinable properties without thereby having a unique determinate of that determinable.

Sign in / Sign up

Export Citation Format

Share Document