Chapter 06. De Broglie’s Observations

Muhammad Suhail Zubairy

In 1924, de Broglie postulated that particles can behave like waves, thus complementing the observation by Einstein in 1905 that light can behave like particles. This wave–particle duality aspect for both particles and waves had a deep impact on the subsequent development of quantum mechanics. Some highly counterintuitive results, like the Heisenberg uncertainty relation and the Bose–Einstein condensation, that were motivated by wave–particle duality are discussed in this chapter. Following de Broglie’s hypothesis, a wave packet description for a particle is described. An analysis of the Heisenberg microscope is presented, thus motivating the Heisenberg uncertainty relation. The Davisson–Germer experiment that showed that electrons can behave like waves and the Compton effect that provided early conclusive evidence that light can behave like particles are also discussed.

Richard Schlegel

Sudipta Das

H. Y. Cui

We show that the relativistic matter waves of two particle system contains the SU(2) symmetry; the relativistic matter waves of three particle system contains the SU(3) symmetry. Therefore, the relativistic matter wave is suitable for describing many-particle system such as quarks or gluons etc that are engaged with implicated symmetry problems. The weak interaction and strong interaction are investigated by using the relativistic de Broglie matter wave with SU(n) symmetry. Our results agree well with experiments. This work is to re-discover and re-explore de Broglie matter wave with the SU(n) symmetry and its applications to particle physics. This work was divided into two parts: Chapter 1, Relativistic de Broglie matter wave; Chapter 2, Factory of prosthesis.

Ram Yatan Prasad, Pranita

This chapter describes the dual nature of electron/de Broglie waves. de Broglie suggested that like light, an electron also behaves as both a particle and a wave. Based on this hypothesis, a relationship between wavelength of electrons (a particle) and momentum was developed. It opines that ‘wavelength of the particle is inversely proportional to momentum’. This is called the de Broglie relation. On the basis of the above facts, we have developed a relationship between wavelength and voltage applied and this relation may be stated as ‘the wavelength of a particle is inversely proportional to the square root of the voltage applied to the system’. This chapter also uses the Davisson and Germer experiment to show the wave nature of the particle, i.e., diffraction of electrons by crystal lattice. The experimental results were the same as found in the case of the diffraction of X-ray by crystals. This chapter also provides an idea on quantisation of angular momentum. It also discusses Heisenberg’s uncertainty principle, phase velocity, group velocity, and uncertainty relation between energy and time. The chapter comprises the experimental evidence of Heisenberg’s uncertainty principle, such as by diffraction of electrons through a slit and gamma ray microscope thought experiment, which is shows the physical significance of the uncertainty principle. Sufficient references, solved problems, and questions on concepts have been provided at the end of chapter.

M. Surdin