Archive of historical materials
The 67th Physics Colloquium: “Cohesive Force in Metals”
OU1935-B5 (10 pages) Date: December 19, 1935
Yukawa attempted to elucidate the crystal structures and electron configurations of metals from the perspective of quantum mechanics. He gained the understanding of the properties of various metals by utilizing the basic equation (Schrödinger equation) of quantum mechanics developed during the period of 1925 to 1926. Yukawa explained to his colleagues in the Department of Physics that electrons were fermions and that quantum mechanics was essential for understanding how the electron orbital configuration in the atom and the crystal structure formed by numerous aggregated atoms were determined by the force induced by the quantum effect. He stressed that quantum mechanics was the key to comprehending the structures of substances. The cohesive force of a metal could be explained based on the principles of quantum mechanics. These ideas have formed the foundation of today’s condensed matter physics, but only a few people understood those ideas in Japan in those years.
In the colloquium, Yukawa gave the detailed explanations of valence electrons, free electron concept and Slater theory before describing the Wigner-Seitz theory. On page 7, he describes the behavior of the electron wave function in sodium (Na) and copper (Cu) by referring to the copy of Wigner and Seitz’s paper. (Written by Yutaka Hosotani)
