Are there quantum jumps

2014 ◽  
Vol 33 ◽  
pp. 1460358
Author(s):  
D. K. Ferry
Keyword(s):  
Perturbation Theory ◽  
Quantum Mechanics ◽  
Time Dependence ◽  
Quantum States ◽  
Smooth Transition ◽  
Wave Mechanics ◽  
Incoming Wave ◽  
Quantum Jumps ◽  
Quantum Jump ◽  
History Of

Generally, one thinks of a “quantum jump” as the process in which an electron “jumps” between a pair of quantum states, even as the process is treated within perturbation theory. This jump of an electron has remained a key point of conservative (i.e., traditional) quantum mechanics. But, the question of the time dependence of such a transition, e.g. the time for an atom to be ionized by radiation, is somewhat different than this view. A detailed approach in which an incoming wave first polarizes the quantum states and then completes the transition has allowed for a detailed discussion of the smooth transition of the electron from one state to the next. Here, we will discuss the history of the process, and illustrate the approach with the question of “how long does it take for an electron to emit a phonon?” The entire process arises from the proper application of wave mechanics and obviates the need to even consider a discussion of quantum jumps.

scholarly journals Perturbation problems in quantum mechanics

1930 ◽  
Vol 129 (811) ◽  
pp. 598-615 ◽  
Keyword(s):  
Molecular Structure ◽  
Perturbation Theory ◽  
Quantum Mechanics ◽  
Present Form ◽  
Wave Mechanics ◽  
Mathematical Technique ◽  
Important Advance ◽  
Complex Problems ◽  
Perturbation Problems ◽  
Improved Methods

One of the great achievements of the Schrödinger wave-mechanics is the elegance of its perturbation theory, which has brought many problems, formerly considered intractable, within the range of a highly-developed mathematical technique. It is not necessary at this stage to review the numerous applications which have been made of this perturbation theory or to dwell upon its many advantages. The important advance towards an understanding of chemical forces which it has made possible is in itself a considerable achievement. There are, however, certain disadvantages in the perturbation theory in its present form, which limit the extent of its applications to complex problems of atomic and molecular structure. If the interaction of atoms, for instance, is to be calculated, as it most desirable, improved methods will have to be found.

Introduction

2017 ◽  
Author(s):  
Henk W. de Regt
Keyword(s):  
Quantum Mechanics ◽  
History Of Science ◽  
Crucial Role ◽  
Scientific Understanding ◽  
Related Question ◽  
History Of ◽  
Human Desire ◽  
Exciting Project ◽  
Understanding Science ◽  
The Way

This chapter introduces the theme of the book: scientific understanding. Science is arguably the most successful product of the human desire for understanding. Reflection on the nature of scientific understanding is an important and exciting project for philosophers of science, as well as for scientists and interested laypeople. As a first illustration of this, the chapter sketches an episode from the history of science in which discussions about understanding played a crucial role: the genesis of quantum mechanics in the 1920s, and the heated debates about the intelligibility of this theory and the related question of whether it can provide understanding. This case shows that standards of intelligibility of scientists can vary strongly. Furthermore, the chapter outlines and defends the way in which this study approaches its subject, differing essentially from mainstream philosophical discussions of explanatory understanding. It concludes with an overview of the contents of the book.

Quantum Theory

2017 ◽  
Author(s):  
Frank S. Levin
Keyword(s):  
Quantum Mechanics ◽  
Quantum Theory ◽  
Uncertainty Principle ◽  
Quantum Spin ◽  
Quantum States ◽  
Wave Functions ◽  
Symbolic Representations ◽  
Quantum Numbers ◽  
The Subject ◽  
Heisenberg's Uncertainty Principle

The subject of Chapter 8 is the fundamental principles of quantum theory, the abstract extension of quantum mechanics. Two of the entities explored are kets and operators, with kets being representations of quantum states as well as a source of wave functions. The quantum box and quantum spin kets are specified, as are the quantum numbers that identify them. Operators are introduced and defined in part as the symbolic representations of observable quantities such as position, momentum and quantum spin. Eigenvalues and eigenkets are defined and discussed, with the former identified as the possible outcomes of a measurement. Bras, the counterpart to kets, are introduced as the means of forming probability amplitudes from kets. Products of operators are examined, as is their role underpinning Heisenberg’s Uncertainty Principle. A variety of symbol manipulations are presented. How measurements are believed to collapse linear superpositions to one term of the sum is explored.

Constructing Quantum Mechanics

2019 ◽  
Author(s):  
Anthony Duncan ◽  
Michel Janssen
Keyword(s):  
Quantum Mechanics ◽  
Quantum Theory ◽  
Stark Effect ◽  
Zeeman Effect ◽  
Black Body ◽  
Black Body Radiation ◽  
Wave Mechanics ◽  
Specific Heats ◽  
Old Quantum Theory ◽  
Upper Level

This is the first of two volumes on the genesis of quantum mechanics. It covers the key developments in the period 1900–1923 that provided the scaffold on which the arch of modern quantum mechanics was built in the period 1923–1927 (covered in the second volume). After tracing the early contributions by Planck, Einstein, and Bohr to the theories of black‐body radiation, specific heats, and spectroscopy, all showing the need for drastic changes to the physics of their day, the book tackles the efforts by Sommerfeld and others to provide a new theory, now known as the old quantum theory. After some striking initial successes (explaining the fine structure of hydrogen, X‐ray spectra, and the Stark effect), the old quantum theory ran into serious difficulties (failing to provide consistent models for helium and the Zeeman effect) and eventually gave way to matrix and wave mechanics. Constructing Quantum Mechanics is based on the best and latest scholarship in the field, to which the authors have made significant contributions themselves. It breaks new ground, especially in its treatment of the work of Sommerfeld and his associates, but also offers new perspectives on classic papers by Planck, Einstein, and Bohr. Throughout the book, the authors provide detailed reconstructions (at the level of an upper‐level undergraduate physics course) of the cental arguments and derivations of the physicists involved. All in all, Constructing Quantum Mechanics promises to take the place of older books as the standard source on the genesis of quantum mechanics.

Transmitting Knowledge across Divides

2016 ◽  
Vol 46 (3) ◽  
pp. 313-359 ◽  
Author(s):  
Marta Jordi Taltavull
Keyword(s):  
Experimental Data ◽  
Quantum Mechanics ◽  
Quantum Theory ◽  
Scientific Understanding ◽  
Resonance Model ◽  
Optical Dispersion ◽  
History Of

One model, the resonance model, shaped scientific understanding of optical dispersion from the early 1870s to the 1920s, persisting across dramatic changes in physical conceptions of light and matter. I explore the ways in which the model was transmitted across these conceptual divides by analyzing the use of the model both in the development of theories of optical dispersion and in the interpretation of experimental data. Crucial to this analysis is the integration of the model into quantum theory because of the conceptual incompatibility between the model and quantum theory. What is more, a quantum understanding of optical dispersion set the grounds for the emergence of the first theories of quantum mechanics in 1925. A long-term history of the model’s transmission from the 1870s to the 1920s illuminates the ways in which the continuity of knowledge is possible across these discontinuities.

“QUANTUM JUMPS” AND INDISTINGUISHABILITY

1989 ◽  
Vol 04 (19) ◽  
pp. 1839-1845 ◽  
Author(s):  
ADRIAN KENT
Keyword(s):  
Quantum Mechanics ◽  
Relativistic Quantum ◽  
Relativistic Quantum Mechanics ◽  
Model Parameters ◽  
Quantum Jumps ◽  
Cover Systems

Ghirardi, Rimini and Weber have presented a statistical modification of non-relativistic quantum mechanics which unifies the description of microscopic and macroscopic systems of distinct particles. We revise their proposal to cover systems of indistinguishable particles. Testable, mathematically precise, realist models of non-relativistic physics result. We give empirically derived bounds on the model parameters.

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