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## Física quântica e formação docente: confluência de várias redes; Quantum Physics and Teacher Training: Confluence of Several Networks

Fonte: Biblioteca Digitais de Teses e Dissertações da USP
Publicador: Biblioteca Digitais de Teses e Dissertações da USP

Tipo: Tese de Doutorado
Formato: application/pdf

Publicado em 07/05/2014
PT

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#Complex networks#Complexidade e aprendizagem#Complexity and learning#Física (estudo e ensino)#Física quântica#Formação de professores#Physics (study and teaching)#Quantum physics#Redes complexas#Teacher training

Tendo reformulado a mecânica surgida da termoestatística das radiações eletromagnéticas, a física quântica abriu o caminho nas baixas energias para a complexidade dos materiais e da vida, e nas altas energias para as partículas elementares e conexões cosmológicas. Entre as demais ciências, ela fundamenta a química fina, a biologia molecular e inúmeras aplicações práticas. No cotidiano tecnológico, através dos semicondutores e lasers da microeletrônica, a quântica é a alma conceitual das telecomunicações e das redes informáticas, instrumentando todas as atividades humanas, das relações pessoais às práticas médicas, e condicionando a emergência de uma sociedade em rede. Em associação com as tecnologias que promove, o domínio quântico tem sido central na investigação das redes complexas que transforma a compreensão de processos naturais, tecnológicos e sociais. Das redes neurais às sociais, qualquer campo de atividade e de conhecimento está sendo modificado ou desequilibrado pela percepção de seu caráter complexo. Impactada pelo novo ambiente, a educação já se desenvolve com recursos em rede amplamente difundidos e revê a conceituação do aprender como algo complexo e em rede em lugar da velha sequência linear de conteúdos. Sendo convergência e fonte de várias redes...

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## 8.06 Quantum Physics III, Spring 2003; Quantum Physics III

Fonte: MIT - Massachusetts Institute of Technology
Publicador: MIT - Massachusetts Institute of Technology

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EN-US

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#natural units#scales of microscopic phenomena#Time-independent approximation methods: degenerate and non-degenerate perturbation theory#variational method#Born-Oppenheimer approximation#spin-orbit and relativistic corrections#Zeeman and Stark effects#Charged particles in a magnetic field#Landau levels#integer quantum hall effect#Scattering

Continuation of 8.05. Units: natural units, scales of microscopic phenomena, applications. Time-independent approximation methods: degenerate and non-degenerate perturbation theory, variational method, Born-Oppenheimer approximation, applications to atomic and molecular systems. The structure of one- and two-electron atoms: overview, spin-orbit and relativistic corrections, fine structure, variational approximation, screening, Zeeman and Stark effects. Charged particles in a magnetic field: Landau levels and integer quantum hall effect. Scattering: general principles, partial waves, review of one-dimension, low-energy approximations, resonance, Born approximation. Time-dependent perturbation theory. Students research and write a paper on a topic related to the content of 8.05 and 8.06. From the course home page: Course Description This course is a continuation of 8.05, Quantum Physics II. Content includes: Natural Units Charged particles in a magnetic field Time-independent perturbation theory Variational and semi-classical methods Quantum Computing The adiabatic approximation and Berry’s phase Scattering Time-dependent perturbation theory

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## 8.05 Quantum Physics II, Fall 2002; Quantum Physics II

Fonte: MIT - Massachusetts Institute of Technology
Publicador: MIT - Massachusetts Institute of Technology

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#General formalism of quantum mechanics: states#Dirac notation#representations#measurement theory#states#Quantum mechanics in three-dimensions: central potentials and the radial equation#bound and scattering states#qualitative analysis of wavefunctions#commutator algebra#eigenvalues and eigenstates#spherical harmonics

Together 8.05 and 8.06 cover quantum physics with applications drawn from modern physics. General formalism of quantum mechanics: states, operators, Dirac notation, representations, measurement theory. Harmonic oscillator: operator algebra, states. Quantum mechanics in three-dimensions: central potentials and the radial equation, bound and scattering states, qualitative analysis of wavefunctions. Angular momentum: operators, commutator algebra, eigenvalues and eigenstates, spherical harmonics. Spin: Stern-Gerlach devices and measurements, nuclear magnetic resonance, spin and statistics. Addition of angular momentum: Clebsch-Gordan series and coefficients, spin systems, and allotropic forms of hydrogen.

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## Three Dimensional Time Theory: to Unify the Principles of Basic Quantum Physics and Relativity

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 02/10/2005

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Interpreting quantum mechanics(QM) by classical physics seems like an old
topic; And unified theory is in physics frontier; But because the principles of
quantum physics and relativity are so different, any theories of trying to
unify 4 nature forces should not be considered as completed without truly
unifying the basic principles between QM and relativity. This paper will
interpret quantum physics by using two extra dimensional time as quantum hidden
variables. I'll show that three dimensional time is a bridge to connect basics
quantum physics, relativity and string theory. ``Quantum potential'' in Bohm's
quantum hidden variable theory is derived from Einstein Lagrangian in
6-dimensional time-space geometry. Statistical effect in the measurement of
single particle, non-local properties, de Broglie wave can be naturally derived
from the natural properties of three dimensional time. Berry phase, double-slit
interference of single particle, uncertainty relation, wave-packet collapse are
discussed. The spin and g factor are derived from geometry of extra two time
dimensions. Electron can be expressed as time monopole. In the last part of
this paper, I'll discuss the relation between three dimensional time and
unified theory.
Key words: Quantum hidden variable...

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## Proceedings of the 11th workshop on Quantum Physics and Logic

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 27/12/2014

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#Computer Science - Logic in Computer Science#Computer Science - Computation and Language#Computer Science - Programming Languages#Quantum Physics

This volume contains the proceedings of the 11th International Workshop on
Quantum Physics and Logic (QPL 2014), which was held from the 4th to the 6th of
June, 2014, at Kyoto University, Japan.
The goal of the QPL workshop series is to bring together researchers working
on mathematical foundations of quantum physics, quantum computing and
spatio-temporal causal structures, and in particular those that use logical
tools, ordered algebraic and category-theoretic structures, formal languages,
semantic methods and other computer science methods for the study of physical
behavior in general. Over the past few years, there has been growing activity
in these foundational approaches, together with a renewed interest in the
foundations of quantum theory, which complement the more mainstream research in
quantum computation. Earlier workshops in this series, with the same acronym
under the name "Quantum Programming Languages", were held in Ottawa (2003),
Turku (2004), Chicago (2005), and Oxford (2006). The first QPL under the new
name Quantum Physics and Logic was held in Reykjavik (2008), followed by Oxford
(2009 and 2010), Nijmegen (2011), Brussels (2012) and Barcelona (2013).

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## Quantum Physics and Classical Physics - in the Light of Quantum Logic

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

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In contrast to the Copenhagen interpretation we consider quantum mechanics as
universally valid and query whether classical physics is really intuitive and
plausible. - We discuss these problems within the quantum logic approach to
quantum mechanics where the classical ontology is relaxed by reducing
metaphysical hypotheses. On the basis of this weak ontology a formal logic of
quantum physics can be established which is given by an orthomodular lattice.
By means of the Soler condition and Piron's result one obtains the classical
Hilbert spaces. - However, this approach is not fully convincing. There is no
plausible justification of Soler's law and the quantum ontology is partly too
weak and partly too strong. We propose to replace this ontology by an ontology
of unsharp properties and conclude that quantum mechanics is more intuitive
than classical mechanics and that classical mechanics is not the macroscopic
limit of quantum mechanics.; Comment: 10 pages, LaTeX, to appear in Int. Jour. Theo. Phys, few typos
corrected

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## Exploring the Quantum Speed Limit with Computer Games

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

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Humans routinely solve problems of immense computational complexity by
intuitively forming simple, low-dimensional heuristic strategies. Citizen
science exploits this intuition by presenting scientific research problems to
non-experts. Gamification is an effective tool for attracting citizen
scientists and allowing them to provide novel solutions to the research
problems. Citizen science games have been used successfully in Foldit, EteRNA
and EyeWire to study protein and RNA folding and neuron mapping. However,
gamification has never been applied in quantum physics. Everyday experiences of
non-experts are based on classical physics and it is \textit{a priori} not
clear that they should have an intuition for quantum dynamics. Does this
premise hinder the use of citizen scientists in the realm of quantum mechanics?
Here we report on Quantum Moves, an online platform gamifying optimization
problems in quantum physics. Quantum Moves aims to use human players to find
solutions to a class of problems associated with quantum computing. Players
discover novel solution strategies which numerical optimizations fail to find.
Guided by player strategies, a new low-dimensional heuristic optimization
method is formed, efficiently outperforming the most prominent established
methods. We have developed a low-dimensional rendering of the optimization
landscape showing a growing complexity when the player solutions get fast.
These fast results offer new insight into the nature of the so-called Quantum
Speed Limit. We believe that an increased focus on heuristics and landscape
topology will be pivotal for general quantum optimization problems beyond the
type presented here.; Comment: 18 pages...

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## Testing quantum physics in space using high-mass matter-wave interferometry

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 31/08/2015

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Quantum superposition is central to quantum theory but challenges our
concepts of reality and spacetime when applied to macroscopic objects like
Schr\"odinger's cat. For that reason, it has been a long-standing question
whether quantum physics remains valid unmodified even for truly macroscopic
objects. By now, the predictions of quantum theory have been confirmed via
matter-wave interferometry for massive objects up to $10^4\,$ atomic mass units
(amu). The rapid development of new technologies promises to soon allow tests
of quantum theory for significantly higher test masses by using novel
techniques of quantum optomechanics and high-mass matter-wave interferometry.
Such experiments may yield novel insights into the foundations of quantum
theory, pose stringent limits on alternative theoretical models or even uncover
deviations from quantum physics. However, performing experiments of this type
on Earth may soon face principal limitations due to requirements of long times
of flight, ultra-low vibrations, and extremely high vacuum. Here, we present a
short overview of recent developments towards the implementation of the
proposed space-mission MAQRO, which promises to overcome those limitations and
to perform matter-wave interferometry in a parameter regime orders of magnitude
beyond state-of-the-art.; Comment: 4 pages...

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## Can classical physics agree with quantum physics on quantum phenomena?

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 13/04/2015

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Classical physics fails where quantum physics prevails. This common
understanding applies to quantum phenomena that are acknowledged to be beyond
the reach of classical physics. Here, we make an attempt at weakening this
solid belief that classical physics is unfit to explain the quantum world. The
trial run is the quantization of the free radiation field that will be
addressed by following a strategy that is free from operators or
quantum-mechanical concepts; Comment: 9 pages

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## Correlations in Quantum Physics

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 24/08/2012

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We provide an historical perspective of how the notion of correlations has
evolved within quantum physics. We begin by reviewing Shannon's information
theory and its first application in quantum physics, due to Everett, in
explaining the information conveyed during a quantum measurement. This
naturally leads us to Lindblad's information theoretic analysis of quantum
measurements and his emphasis of the difference between the classical and
quantum mutual information. After briefly summarising the quantification of
entanglement using these and related ideas, we arrive at the concept of quantum
discord that naturally captures the boundary between entanglement and classical
correlations. Finally we discuss possible links between discord and the
generation of correlations in thermodynamic transformations of coupled harmonic
oscillators.; Comment: 10 pages, 1 figure. Submitted to Int. J. Mod. Phys. B, special issue
"Classical Vs Quantum correlations in composite systems" edited by L. Amico,
S. Bose, V. Korepin and V. Vedral

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## Unitary Quantum Physics with Time-Space Noncommutativity

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

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#High Energy Physics - Theory#General Relativity and Quantum Cosmology#Mathematical Physics#Mathematics - Quantum Algebra#Quantum Physics

In this work quantum physics in noncommutative spacetime is developed. It is
based on the work of Doplicher et al. which allows for time-space
noncommutativity. The Moyal plane is treated in detail. In the context of
noncommutative quantum mechanics, some important points are explored, such as
the formal construction of the theory, symmetries, causality, simultaneity and
observables. The dynamics generated by a noncommutative Schrodinger equation is
studied. We prove in particular the following: suppose the Hamiltonian of a
quantum mechanical particle on spacetime has no explicit time dependence, and
the spatial coordinates commute in its noncommutative form (the only
noncommutativity being between time and a space coordinate). Then the
commutative and noncommutative versions of the Hamiltonian have identical
spectra.; Comment: 18 pages, published version

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## Noncommutative analysis and quantum physics I. States and ensembles

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 26/09/1999

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In this sequence of papers, noncommutative analysis is used to give a
consistent axiomatic approach to a unified conceptual foundation of classical
and quantum physics.
The present Part I defines the concepts of observables, states and ensembles,
clarifies the logical relations and operations for them, and shows how they
give rise to dynamics and probabilities.
States are identified with maximal consistent sets of weak equalities in the
algebra of observables (instead of, as usual, with the rays in a Hilbert
space). This leads to a concise foundation of quantum mechanics, free of
undefined terms, separating in a clear way the deterministic and the stochastic
features of quantum physics.
The traditional postulates of quantum mechanics are derived from
well-motivated axiomatic assumptions. No special quantum logic is needed to
handle the peculiarities of quantum mechanics. Foundational problems associated
with the measurement process, such as the reduction of the state vector,
disappear.
The new interpretation of quantum mechanics contains `elements of physical
reality' without the need to introduce a classical framework with hidden
variables. In particular, one may talk about the state of the universe without
the need of an external observer and without the need to assume the existence
of multiple universes.; Comment: 38 pages

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## Interpretive Themes in Quantum Physics: Curriculum Development and Outcomes

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 25/08/2011

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A common learning goal for modern physics instructors is for students to
recognize a difference between the experimental uncertainty of classical
physics and the fundamental uncertainty of quantum mechanics. Our prior work
has shown that student perspectives on the physical interpretation of quantum
mechanics can be characterized, and are differentially influenced by the myriad
ways instructors approach interpretive themes in their introductory courses. We
report how a transformed modern physics curriculum (recently implemented at the
University of Colorado) has positively impacted student perspectives on quantum
physics, by making questions of classical and quantum reality a central theme
of the course, but also by making the beliefs of students (and not just those
of scientists) an explicit topic of discussion.; Comment: Supporting materials available at
http://tinyurl.com/baily-dissertation

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## Refined Characterization of Student Perspectives on Quantum Physics

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 29/08/2011

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The perspectives of introductory classical physics students can often
negatively influence how those students later interpret quantum phenomena when
taking an introductory course in modern physics. A detailed exploration of
student perspectives on the interpretation of quantum physics is needed, both
to characterize student understanding of physics concepts, and to inform how we
might teach traditional content. Our previous investigations of student
perspectives on quantum physics have indicated they can be highly nuanced, and
may vary both within and across contexts. In order to better understand the
contextual and often seemingly contradictory stances of students on matters of
interpretation, we interviewed 19 students from four introductory modern
physics courses taught at the University of Colorado. We find that students
have attitudes and opinions that often parallel the stances of expert
physicists when arguing for their favored interpretations of quantum mechanics,
allowing for more nuanced characterizations of student perspectives in terms of
three key interpretive themes. We present a framework for characterizing
student perspectives on quantum mechanics, and demonstrate its utility in
interpreting the sometimes-contradictory nature of student responses to
previous surveys. We further find that students most often vacillate in their
responses when what makes intuitive sense to them is not in agreement with what
they consider to be a correct response...

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## A Class of Deductive Theories that cannot be Deterministic: Classical and Quantum Physics are not deterministic

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

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The problem of the determinism of Quantum Mechanics has been a main one
during the 20th century. At the same time, in the context of Logic and Set
Theory, the importance of ancient paradoxes as well as the appearance of many
new ones, has shed light on and deeply influenced the foundations of
Mathematics and somehow of Physics. But, strangely, concerning Physics, a
paradox which we call the Memory Paradox has remained yet undiscovered, despite
its simplicity and remarkable consequences, mostly in Physics and surprisingly
in classical Physics that appear to be non deterministic, contrary to the
general belief since Newton, Laplace, etc.. The non determinism of Quantum
Physics follows without any supplementary hypothesis. This paper extends a
previous one (arXiv: 1203.2945v1 [physics.gen-ph] 13 Mar 2012).; Comment: 4 pages (the first version has only 2); the case of classical physics
is treated explicitly

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## How to account for quantum non-locality: ontic structural realism and the primitive ontology of quantum physics

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 28/08/2014

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The paper has two aims: (1) it sets out to show that it is well motivated to
seek for an account of quantum non-locality in the framework of ontic
structural realism (OSR), which integrates the notions of holism and
non-separability that have been employed since the 1980s to achieve such an
account. However, recent research shows that OSR on its own cannot provide such
an account. Against this background, the paper argues that by applying OSR to
the primitive ontology theories of quantum physics, one can accomplish that
task. In particular, Bohmian mechanics offers the best prospect for doing so.
(2) In general, the paper seeks to bring OSR and the primitive ontology
theories of quantum physics together: on the one hand, in order to be
applicable to quantum mechanics, OSR has to consider what the quantum ontology
of matter distributed in space-time is. On the other hand, as regards the
primitive ontology theories, OSR provides the conceptual tools for these
theories to answer the question of what the ontological status of the
wave-function is.; Comment: arXiv admin note: substantial text overlap with arXiv:1406.0732

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## The Oxford Questions on the foundations of quantum physics

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 04/07/2013

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The twentieth century saw two fundamental revolutions in physics --
relativity and quantum. Daily use of these theories can numb the sense of
wonder at their immense empirical success. Does their instrumental
effectiveness stand on the rock of secure concepts or the sand of unresolved
fundamentals? Does measuring a quantum system probe, or even create, reality,
or merely change belief? Must relativity and quantum theory just co-exist or
might we find a new theory which unifies the two? To bring such questions into
sharper focus, we convened a conference on Quantum Physics and the Nature of
Reality. Some issues remain as controversial as ever, but some are being nudged
by theory's secret weapon of experiment.; Comment: 8 pages

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## Pascual Jordan, his contributions to quantum mechanics and his legacy in contemporary local quantum physics

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

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#High Energy Physics - Theory#General Relativity and Quantum Cosmology#High Energy Physics - Phenomenology#Mathematical Physics#Quantum Physics

After recalling episodes from Pascual Jordan's biography including his
pivotal role in the shaping of quantum field theory and his much criticized
conduct during the NS regime, I draw attention to his presentation of the first
phase of development of quantum field theory in a talk presented at the 1929
Kharkov conference. He starts by giving a comprehensive account of the
beginnings of quantum theory, emphasising that particle-like properties arise
as a consequence of treating wave-motions quantum-mechanically. He then goes on
to his recent discovery of quantization of ``wave fields'' and problems of
gauge invariance. The most surprising aspect of Jordan's presentation is
however his strong belief that his field quantization is a transitory not yet
optimal formulation of the principles underlying causal, local quantum physics.
The expectation of a future more radical change coming from the main architect
of field quantization already shortly after his discovery is certainly quite
startling. I try to answer the question to what extent Jordan's 1929
expectations have been vindicated. The larger part of the present essay
consists in arguing that Jordan's plea for a formulation without ``classical
correspondence crutches'', i.e. for an intrinsic approach (which avoids
classical fields altogether)...

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## What we can learn about quantum physics from a single qubit

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 05/12/2013

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We present an approach for teaching quantum physics at high school level
based on the simplest quantum system - the single quantum bit (qubit). We show
that many central concepts of quantum mechanics, including the superposition
principle, the stochastic behavior and state change under measurements as well
as the Heisenberg uncertainty principle can be understood using simple
mathematics, and can be illustrated using catchy visualizations. We discuss
abstract features of a qubit in general, and consider possible physical
realizations as well as various applications, e.g. in quantum cryptography.; Comment: 15 pages, 19 figures

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## Quantum physics meets biology

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 01/11/2009

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Quantum physics and biology have long been regarded as unrelated disciplines,
describing nature at the inanimate microlevel on the one hand and living
species on the other hand. Over the last decades the life sciences have
succeeded in providing ever more and refined explanations of macroscopic
phenomena that were based on an improved understanding of molecular structures
and mechanisms. Simultaneously, quantum physics, originally rooted in a world
view of quantum coherences, entanglement and other non-classical effects, has
been heading towards systems of increasing complexity. The present perspective
article shall serve as a pedestrian guide to the growing interconnections
between the two fields. We recapitulate the generic and sometimes unintuitive
characteristics of quantum physics and point to a number of applications in the
life sciences. We discuss our criteria for a future quantum biology, its
current status, recent experimental progress and also the restrictions that
nature imposes on bold extrapolations of quantum theory to macroscopic
phenomena.; Comment: 26 pages, 4 figures, Perspective article for the HFSP Journal

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