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Books > Science & Mathematics > Physics > Quantum physics (quantum mechanics)
Electrostatic forces are essential for the hierarchical structure
of matter: electrons are bound to the atomic nucleus by
electrostatic forces; atoms carry (partial) charges and ions with
opposite charges attract and form (chemical) bonds. Small residual
electrostatic forces between molecules allow them to form
macroscopic structures such as crystals. Electrostatic interactions
explain pseudo-forces used in popular computer programs used to
model properties of atoms, molecules, and proteins. By beginning
with the basics and then diving deeper into the topic, this book
aims to familiarize the reader with electrostatic forces at the
atomic and molecular level.
Like rocket science or brain surgery, quantum mechanics is
pigeonholed as a daunting and inaccessible topic, which is best
left to an elite or peculiar few. This classification was not
earned without some degree of merit. Depending on perspective;
quantum mechanics is a discipline or philosophy, a convention or
conundrum, an answer or question. Authors have run the gamut from
hand waving to heavy handed in hopes to dispel the common beliefs
about quantum mechanics, but perhaps they continue to promulgate
the stigma. The focus of this particular effort is to give the
reader an introduction, if not at least an appreciation, of the
role that linear algebra techniques play in the practical
application of quantum mechanical methods. It interlaces aspects of
the classical and quantum picture, including a number of both
worked and parallel applications. Students with no prior experience
in quantum mechanics, motivated graduate students, or researchers
in other areas attempting to gain some introduction to quantum
theory will find particular interest in this book.
The results of renormalized perturbation theory, in QCD and other
quantum field theories, are ambiguous at any finite order, due to
renormalization-scheme dependence. The perturbative results depend
upon extraneous scheme variables, including the renormalization
scale, that the exact result cannot depend on. Such 'non-invariant
approximations' occur in many other areas of physics, too. The
sensible strategy is to find where the approximant is stationary
under small variations of the extraneous variables. This general
principle is explained and illustrated with various examples. Also
dimensional transmutation, RG equations, the essence of
renormalization and the origin of its ambiguities are explained in
simple terms, assuming little or no background in quantum field
theory. The minimal-sensitivity approach leads to 'optimized
perturbation theory,' which is developed in detail. Applications to
Re+e-, the infrared limit, and to the optimization of factorized
quantities, are also discussed thoroughly.
This book and its prequel (Theories of Matter, Space, and Time:
Classical Theories) grew out of courses that are taught by the
authors on the undergraduate degree program in physics at
Southampton University, UK. The authors aim to guide the full MPhys
undergraduate cohort through some of the trickier areas of
theoretical physics that undergraduates are expected to master. To
move beyond the initial courses in classical mechanics, special
relativity, electromagnetism and quantum theory to more
sophisticated views of these subjects and their interdependence.
This approach keeps the analysis as concise and physical as
possible whilst revealing the key elegance in each subject
discussed.This second book of the pair looks at ideas to the arena
of Quantum Mechanics. First quickly reviewing the basics of quantum
mechanics which should be familiar to the reader from a first
course, it then links the Schrodinger equation to the Principle of
Least Action introducing Feynman's path integral methods. Next, it
presents the relativistic wave equations of Klein, Gordon and
Dirac. Finally, Maxwell's equations of electromagnetism are
converted to a wave equation for photons and make contact with
Quantum Electrodynamics (QED) at a first quantized level. Between
the two volumes the authors hope to move a student's understanding
from their first courses to a place where they are ready to embark
on graduate level courses on quantum field theory.
This book explicates the optical controls of antiferromagnetic
spins by intense terahertz (THz) electromagnetic waves. The book
comprises two key components: (1) the experimental demonstration of
the enhancement of a THz magnetic field using a split-ring
resonator (SRR) and (2) the control of the direction of
magnetization by using the enhanced THz magnetic field to break the
symmetry of optically-induced phase transition. These make up the
first step leading to future spintronics devices. In the beginning
of the book, the author reviews the basics of the ultrafast laser
and nonlinear optical techniques as well as the previously achieved
experiments to control spin dynamics by THz magnetic fields. In
this context, a new experimental protocol is described, in which
electron spins in a ferromagnetic material are redirected at the
unprecedented level in cooperation with the enhanced THz magnetic
field. Subsequently, the author demonstrates that the THz magnetic
field is significantly amplified as a nearfield around the SRR
structured metamaterial, which is implemented by measuring spin
precession in a solid. At the end, the author presents the key
experiment in which the amplified THz magnetic nearfield is applied
to the weak ferromagnet ErFeO3 along with the femtosecond
near-infrared pulse, demonstrating the successful control of
symmetry breaking of the spin system due to coherent control of the
optically-induced spin reorientation phase transition pathways. The
comprehensive introductory review in this book allows readers to
overview state-of-the-art terahertz spectroscopic techniques. In
addition, the skillful description of the experiments is highly
informative for readers in ultrafast magnonics, ultrafast optics,
terahertz technology and plasmonic science.
Domain theory, a subject that arose as a response to natural
concerns in the semantics of computation, studies ordered sets
which possess an unusual amount of mathematical structure. This
book explores its connection with quantum information science and
the concept that relates them: disorder. This is not a literary
work. It can be argued that its subject, domain theory and quantum
information science, does not even really exist, which makes the
scope of this alleged 'work' irrelevant. BUT, it does have a
purpose and to some extent, it can also be said to have a method. I
leave the determination of both of those largely to you, the
reader. Except to say, I am hoping to convince the uninitiated to
take a look. A look at what? Twenty years ago, I failed to
satisfactorily prove a claim that I still believe: that there is
substantial domain theoretic structure in quantum mechanics and
that we can learn a lot from it. One day it will be proven to the
point that people will be comfortable dismissing it as a
'well-known' idea that many (possibly including themselves) had
long suspected but simply never bothered to write down. They may
even call it "obvious!" I will not bore you with a brief history
lesson on why it is not obvious, except to say that we have never
been interested in the difficulty of proving the claim only in
establishing its validity. This book then documents various
attempts on my part to do just that.
This introduction to quantum field theory (QFT) is written by a
physical chemist for physical chemists, chemical physicists, and
other non-physicists with knowledge of quantum theory but who want
to explore ways in which they might use the power of QFT in their
investigations. This book starts where many graduate courses in
quantum theory that are offered to chemistry students leave off and
first develops some of the necessary tools, such as Fock algebra,
which is applied to solving the quantum oscillator problem. Then it
is used to develop the theory of coherent states, time-dependent
perturbation theory, and the treatment of bosons and fermions. With
this background, the QFT of a perfect gas is derived and a
connection to thermodynamics is demonstrated. Application to
imperfect gases provides a new approach to modelling gas-liquid
phase transitions. The book concludes with photons and their
interaction with molecular ensembles, and brings us to full circle
by deriving the blackbody radiation law, which started it all. The
power of the QFT methodology and the breadth of its applications
should fascinate the reader as it has the author.
This book provides an itinerary to quantum mechanics taking into
account the basic mathematics to formulate it. Specifically, it
features the main experiments and postulates of quantum mechanics
pointing out their mathematical prominent aspects showing how
physical concepts and mathematical tools are deeply intertwined.
The material covers topics such as analytic mechanics in Newtonian,
Lagrangian, and Hamiltonian formulations, theory of light as
formulated in special relativity, and then why quantum mechanics is
necessary to explain experiments like the double-split, atomic
spectra, and photoelectric effect. The Schroedinger equation and
its solutions are developed in detail. It is pointed out that,
starting from the concept of the harmonic oscillator, it is
possible to develop advanced quantum mechanics. Furthermore, the
mathematics behind the Heisenberg uncertainty principle is
constructed towards advanced quantum mechanical principles.
Relativistic quantum mechanics is finally considered.The book is
devoted to undergraduate students from University courses of
Physics, Mathematics, Chemistry, and Engineering. It consists of 50
self-contained lectures, and any statement and theorem are
demonstrated in detail. It is the companion book of "A Mathematical
Journey to Relativity", by the same Authors, published by Springer
in 2020.
Volume 3 of this three-part series presents more advanced topics
and applications of relativistic quantum field theory. The
application of quantum chromodynamics to high-energy particle
scattering is discussed with concrete examples for how to compute
QCD scattering cross sections. Experimental evidence for the
existence of quarks and gluons is then presented both within the
context of the naive quark model and beyond. Dr Strickland then
reviews our current understanding of the weak interaction, the
unified electroweak theory, and the Brout-Higgs-Englert mechanism
for the generation of gauge boson masses. The last two chapters
contain a self-contained introduction to finite temperature quantum
field theory with concrete examples focusing on the
high-temperature thermodynamics of scalar field theories, QED, and
QCD.
This book explains the Lorentz mathematical group in a language
familiar to physicists. While the three-dimensional rotation group
is one of the standard mathematical tools in physics, the Lorentz
group of the four-dimensional Minkowski space is still very strange
to most present-day physicists. It plays an essential role in
understanding particles moving at close to light speed and is
becoming the essential language for quantum optics, classical
optics, and information science. The book is based on papers and
books published by the authors on the representations of the
Lorentz group based on harmonic oscillators and their applications
to high-energy physics and to Wigner functions applicable to
quantum optics. It also covers the two-by-two representations of
the Lorentz group applicable to ray optics, including cavity,
multilayer and lens optics, as well as representations of the
Lorentz group applicable to Stokes parameters and the Poincare
sphere on polarization optics.
Randomness is an active element relevant to all scientific
activities. The book explores the way in which randomness suffuses
the human experience, starting with everyday chance events,
followed by developments into modern probability theory,
statistical mechanics, scientific data analysis, quantum mechanics,
and quantum gravity. An accessible introduction to these theories
is provided as a basis for going into deeper topics.Fowler unveils
the influence of randomness in the two pillars of science,
measurement and theory. Some emphasis is placed on the need and
methods for optimal characterization of uncertainty. An example of
the cost of neglecting this is the St. Petersburg Paradox, a
theoretical game of chance with an infinite expected payoff value.
The role of randomness in quantum mechanics reveals another
particularly interesting finding: that in order for the physical
universe to function as it does and permit conscious beings within
it to enjoy sanity, irreducible randomness is necessary at the
quantum level.The book employs a certain level of mathematics to
describe physical reality in a more precise way that avoids the
tendency of nonmathematical descriptions to be occasionally
misleading. Thus, it is most readily digested by young students who
have taken at least a class in introductory calculus, or
professional scientists and engineers curious about the book's
topics as a result of hearing about them in popular media. Readers
not inclined to savor equations should be able to skip certain
technical sections without losing the general flow of ideas. Still,
it is hoped that even readers who usually avoid equations will give
those within these pages a chance, as they may be surprised at how
potentially foreboding concepts fall into line when one makes a
legitimate attempt to follow a succession of mathematical
implications.
The first version of quantum theory, developed in the mid 1920's,
is what is called nonrelativistic quantum theory; it is based on a
form of relativity which, in a previous volume, was called Newton
relativity. But quickly after this first development, it was
realized that, in order to account for high energy phenomena such
as particle creation, it was necessary to develop a quantum theory
based on Einstein relativity. This in turn led to the development
of relativistic quantum field theory, which is an intrinsically
many-body theory. But this is not the only possibility for a
relativistic quantum theory. In this book we take the point of view
of a particle theory, based on the irreducible representations of
the Poincare group, the group that expresses the symmetry of
Einstein relativity. There are several ways of formulating such a
theory; we develop what is called relativistic point form quantum
mechanics, which, unlike quantum field theory, deals with a fixed
number of particles in a relativistically invariant way. A central
issue in any relativistic quantum theory is how to introduce
interactions without spoiling relativistic invariance. We show that
interactions can be incorporated in a mass operator, in such a way
that relativistic invariance is maintained. Surprisingly for a
relativistic theory, such a construction allows for instantaneous
interactions; in addition, dynamical particle exchange and particle
production can be included in a multichannel formulation of the
mass operator. For systems of more than two particles, however,
straightforward application of such a construction leads to the
undesirable property that clusters of widely separated particles
continue to interact with one another, even if the interactions
between the individual particles are of short range. A significant
part of this volume deals with the solution of this problem. Since
relativistic quantum mechanics is not as well-known as relativistic
quantum field theory, a chapter is devoted to applications of point
form quantum mechanics to nuclear physics; in particular we show
how constituent quark models can be used to derive electromagnetic
and other properties of hadrons.
This textbook is a unique and ambitious primer of nuclear physics,
which introduces recent theoretical and experimental progresses
starting from basics in fundamental quantum mechanics. The
highlight is to offer an overview of nuclear structure phenomena
relevant to recent key findings such as unstable halo nuclei,
superheavy elements, neutron stars, nucleosynthesis, the standard
model, lattice quantum chromodynamics (LQCD), and chiral effective
theory. An additional attraction is that general properties of
nuclei are comprehensively explained from both the theoretical and
experimental viewpoints. The book begins with the conceptual and
mathematical basics of quantum mechanics, and goes into the main
point of nuclear physics - nuclear structure, radioactive ion beam
physics, and nuclear reactions. The last chapters devote
interdisciplinary topics in association with astrophysics and
particle physics. A number of illustrations and exercises with
complete solutions are given. Each chapter is comprehensively
written starting from fundamentals to gradually reach modern
aspects of nuclear physics with the objective to provide an
effective description of the cutting edge in the field.
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