Semiclassical Dynamics and Relaxation

Semiclassical Dynamics and Relaxation PDF Author: D.S.F. Crothers
Publisher: Springer Science & Business Media
ISBN: 0387743138
Category : Science
Languages : en
Pages : 348

Get Book Here

Book Description
Condensed-matter physics plays an ever increasing role in photonics, electronic and atomic collisions research. Dispersion (Dynamics and Relaxation) includes scattering/collisions in the gaseous phase. It also includes thermal agitation, tunneling and relaxation in the liquid and solid phases. Classical mechanics, classical statistical mechanics, classical relativity and quantum mechanics are all implicated. 'Semiclassical' essentially means that there is a large or asymptotic real parameter. 'Semiclassical' can also mean 'classical with first-order quantal correction', based on an exponentiated Liouville series commencing with a simple pole in the -plane, being Planck's reduced constant and coming with all the attendant connection problems associated with the singularity at the turning or transition point and with the Stokes phenomenon. Equally,' semiclassical' can mean 'electrons described quantally and the heavy particles classically'. This latter gives rise to the so-called impact parameter method based on a pre-assigned classical trajectory. With evermore sophisticated experiments, it has become equally more important to test theory over a wider range of parameters. For instance, at low impact energies in heavy-particle collisions, the inverse velocity is a large parameter; in single-domain ferromagnetism, thermal agitation (including Brownian motion and continuous-time random walks) is faced with a barrier of height 'sigma', a possibly large parameter. Methods of solution include phase-integral analysis, integral transforms and change-of-dependent variable. We shall consider the Schrödinger time-independent and time-dependent equations, the Dirac equation, the Fokker Planck equation, the Langevin equation and the equations of Einstein's classical general relativity equations. There is an increasing tendency among physicists to decry applied mathematics and theoretical physics in favour of computational blackboxes. One may say applied mathematics concerns hard sums and products (and their inverses) but unless one can simplify and sum infinite series of products of infinite series, can one believe the results of a computer program? The era of the polymath has passed; this book proposal aims to show the relevance to, and impact of theory on, laboratory scientists.

Semiclassical Dynamics and Relaxation

Semiclassical Dynamics and Relaxation PDF Author: D.S.F. Crothers
Publisher: Springer Science & Business Media
ISBN: 0387743138
Category : Science
Languages : en
Pages : 348

Get Book Here

Book Description
Condensed-matter physics plays an ever increasing role in photonics, electronic and atomic collisions research. Dispersion (Dynamics and Relaxation) includes scattering/collisions in the gaseous phase. It also includes thermal agitation, tunneling and relaxation in the liquid and solid phases. Classical mechanics, classical statistical mechanics, classical relativity and quantum mechanics are all implicated. 'Semiclassical' essentially means that there is a large or asymptotic real parameter. 'Semiclassical' can also mean 'classical with first-order quantal correction', based on an exponentiated Liouville series commencing with a simple pole in the -plane, being Planck's reduced constant and coming with all the attendant connection problems associated with the singularity at the turning or transition point and with the Stokes phenomenon. Equally,' semiclassical' can mean 'electrons described quantally and the heavy particles classically'. This latter gives rise to the so-called impact parameter method based on a pre-assigned classical trajectory. With evermore sophisticated experiments, it has become equally more important to test theory over a wider range of parameters. For instance, at low impact energies in heavy-particle collisions, the inverse velocity is a large parameter; in single-domain ferromagnetism, thermal agitation (including Brownian motion and continuous-time random walks) is faced with a barrier of height 'sigma', a possibly large parameter. Methods of solution include phase-integral analysis, integral transforms and change-of-dependent variable. We shall consider the Schrödinger time-independent and time-dependent equations, the Dirac equation, the Fokker Planck equation, the Langevin equation and the equations of Einstein's classical general relativity equations. There is an increasing tendency among physicists to decry applied mathematics and theoretical physics in favour of computational blackboxes. One may say applied mathematics concerns hard sums and products (and their inverses) but unless one can simplify and sum infinite series of products of infinite series, can one believe the results of a computer program? The era of the polymath has passed; this book proposal aims to show the relevance to, and impact of theory on, laboratory scientists.

Molecular Excitation Dynamics and Relaxation

Molecular Excitation Dynamics and Relaxation PDF Author: Leonas Valkunas
Publisher: John Wiley & Sons
ISBN: 3527653678
Category : Science
Languages : en
Pages : 414

Get Book Here

Book Description
This work brings together quantum theory and spectroscopy to convey excitation processes to advanced students and specialists wishing to conduct research and understand the entire fi eld rather than just single aspects. Written by experienced authors and recognized authorities in the field, this text covers numerous applications and offers examples taken from different disciplines. As a result, spectroscopists, molecular physicists, physical chemists, and biophysicists will all fi nd this a must-have for their research. Also suitable as supplementary reading in graduate level courses.

Relaxation and Thermalization of Nonequilibrium Quantum Systems in the Semiclassical Limit

Relaxation and Thermalization of Nonequilibrium Quantum Systems in the Semiclassical Limit PDF Author: Rafael Stockschneider Hipolito
Publisher:
ISBN:
Category :
Languages : en
Pages : 430

Get Book Here

Book Description
Abstract: We discuss the development and application of semiclassical techniques to study dynamics and relaxation in quantum mechanical systems out of equilibrium, relevant to ultracold atomic gases. Due to the unprecedented amount of control in these systems, experimentalists have a lot of freedom in designing Hamiltonians, including the spatial dimension. Another advantage present in these systems is the fact that time scales are slow enough, in contradistinction with usual condensed matter systems, so that it is possible to follow nonequilibrium dynamics and relaxation after quantum quenches. The advent of these experiments has motivated us to further understand these systems. With this goal in mind, we apply a semiclassical phase space technique called Truncated Wigner Approximation (TWA) to study dynamics in the weakly interacting, semiclassical limit. In our study, we will further confine ourselves to one dimensional systems where thermalization is poorly understood due to the fact that generic one dimensional Hamiltonians lie close to integrable models. Due to the peculiarity of systems in low dimensions, such as the prohibition of true long range order, these systems relax in an interesting way, and we generically find the emergence of long-lived metastable states. In particular, we find it is possible to design Hamiltonians that share features with the Fermi-Pasta-Ulam model, and these systems relax to a metastable state where different momentum mode energies live at different temperatures.

Quantum and Semi-classical Percolation and Breakdown in Disordered Solids

Quantum and Semi-classical Percolation and Breakdown in Disordered Solids PDF Author: Asok K. Sen
Publisher: Springer Science & Business Media
ISBN: 3540854274
Category : Science
Languages : en
Pages : 334

Get Book Here

Book Description
This lecture notes in physics volume mainly focuses on the semi classical and qu- tum aspects of percolation and breakdown in disordered, composite or granular s- tems. The main reason for this undertaking has been the fact that, of late, there have been a lot of (theoretical) work on quantum percolation, but there is not even a (single) published review on the topic (and, of course, no book). Also, there are many theoretical and experimental studies on the nonlinear current-voltage characteristics both away from, as well as one approaches, an electrical breakdown in composite materials. Some of the results are quite intriguing and may broadly be explained utilising a semi classical (if not, fully quantum mechanical) tunnelling between - cron or nano-sized metallic islands dispersed separated by thin insulating layers, or in other words, between the dangling ends of small percolation clusters. There have also been several (theoretical) studies of Zener breakdown in Mott or Anderson in- lators. Again, there is no review available, connecting them in any coherent fashion. A compendium volume connecting these experimental and theoretical studies should be unique and very timely, and hence this volume. The book is organised as follows. For completeness, we have started with a short and concise introduction on classical percolation. In the ?rst chapter, D. Stauffer reviews the scaling theory of classical percolation emphasizing (biased) diffusion, without any quantum effects. The next chapter by A. K.

Intermolecular and Intramolecular Vibrational Relaxation and Energy Transfer

Intermolecular and Intramolecular Vibrational Relaxation and Energy Transfer PDF Author: Shaul Mukamel
Publisher:
ISBN:
Category :
Languages : en
Pages : 15

Get Book Here

Book Description
This research program resulted in 53 publications. 43 already appeared, 4 are accepted for publication, and 6 were submitted. These publications are listed at the end of the final report. The research focused in the following major areas: (1) molecular semi-classical dynamics in Liouville space; a unified description of vibrational relaxation nonlinear spectroscopy and rate processes; (ii) intramolecular vibrational redistribution; (iii) vibrational and radiative dynamics in molecular clusters; (iv) coherent and spontaneous Raman, fluorescence and four-wave mixing spectroscopy; (v) excitation transport, electron transfer, and localization in disordered molecular systems. The main accomplishments are summarized in the final report. Molecular semiclassical dynamics, Vibrational relaxation, Nonlinear spectroscopy, Energy transfer, Molecular systems. (MJM).

Chaotic Dynamics and Transport in Fluids and Plasmas

Chaotic Dynamics and Transport in Fluids and Plasmas PDF Author: Ilya Prigogine
Publisher: Springer Science & Business Media
ISBN: 9780883189238
Category : Science
Languages : en
Pages : 480

Get Book Here

Book Description
Market: Students and researchers in chaos, plasma physics, and fluid transport. This superb collection of invited papers offers an excellent overview of the current status and future trends in chaotic dynamics, plasma and fluid physics, nonlinear phenomena and chaos, and transport and turbulence studies.

Dielectric Relaxation and Dynamics of Polar Molecules

Dielectric Relaxation and Dynamics of Polar Molecules PDF Author: Vladimir I. Ga?duk
Publisher: World Scientific
ISBN: 9789810221232
Category : Science
Languages : en
Pages : 664

Get Book Here

Book Description
The topics covered in this book provide a qualitative and sometimes quantitative classic description of the wide-band 0-THz dielectric spectra of polar liquids, molecular libration-rotation (which is the reason for dielectric loss and absorption of electromagnetic waves), simple molecular models differing by the intermolecular-potential profiles, and present a comparison between the theoretical and experimental dependencies and derivation of the main results. A new feature is the application of a number of analytical models to different substances, including strongly absorbing nonassociating liquids, liquid water, water bound by macromolecules, and gas-like liquids. The presentation of the theory in this book is also new. It is based on the dynamic method in which the Brownian reorientations are considered implicitly, without direct solution of stochastic equations. This approach simplifies the theory. Senior students and experimentalists will find many of the results valuable.

Spin Dynamics in Radical Pairs

Spin Dynamics in Radical Pairs PDF Author: Alan Lewis
Publisher: Springer
ISBN: 3030006867
Category : Science
Languages : en
Pages : 156

Get Book Here

Book Description
This book sheds new light on the dynamical behaviour of electron spins in molecules containing two unpaired electrons (i.e. a radical pair). The quantum dynamics of these spins are made complicated by the interaction between the electrons and the many nuclear spins of the molecule; they are intractable using analytical techniques, and a naïve numerical diagonalization is not remotely possible using current computational resources. Hence, this book presents a new method for obtaining the exact quantum-mechanical dynamics of radical pairs with a modest number of nuclear spins. Readers will learn how a calculation that would take 13 years using conventional wavepacket propagation can now be done in 1 day, and will also discover a new semiclassical method for approximating the dynamics in the presence of many nuclear spins. The new methods covered in this book are shown to provide significant insights into three topical and diverse areas: charge recombination in molecular wires (which can be used in artificially mimicking photosynthesis), magnetoelectroluminescence in organic light-emitting diodes, and avian magnetoreception (how birds sense the Earth’s magnetic field in order to navigate).

Dynamics of Relaxing Gases

Dynamics of Relaxing Gases PDF Author: John Frederick Clarke
Publisher:
ISBN:
Category : Gas dynamics
Languages : en
Pages : 600

Get Book Here

Book Description


Computer Simulations in Condensed Matter: From Materials to Chemical Biology. Volume 1

Computer Simulations in Condensed Matter: From Materials to Chemical Biology. Volume 1 PDF Author: Mauro Ferrario
Publisher: Springer
ISBN: 3540352732
Category : Science
Languages : en
Pages : 716

Get Book Here

Book Description
This comprehensive collection of lectures by leading experts in the field introduces and reviews all relevant computer simulation methods and their applications in condensed matter systems. Volume 1 is an in-depth introduction to a vast spectrum of computational techniques for statistical mechanical systems of condensed matter. Volume 2 is a collection of state-of-the-art surveys on numerical experiments carried out for a great number of systems.