Broglie, Louis Victor Pierre Raymond de (1892–1987)

French theoretical physicist. He established that all subatomic particles can be described either by particle equations or by wave equations, thus laying the foundations of wave mechanics. He was awarded the Nobel Prize for Physics in 1929 for his discovery of the wavelike nature of electrons. Succeeded as Duke in 1960.

De Broglie's discovery of wave–particle duality enabled physicists to view Einstein's conviction that matter and energy are interconvertible as being fundamental to the structure of matter. The study of matter waves led not only to a much deeper understanding of the nature of the atom but also to explanations of chemical bonds and the practical application of electron waves in electron microscopes.

De Broglie was born in Dieppe and educated at the Sorbonne, where he stayed on until 1928. He was professor at the Henri Poincaré Institute 1932–62. From 1946, he was a senior adviser on the development of atomic energy in France.

If particles could be described as waves, then they must satisfy a partial differential equation known as a wave equation. De Broglie developed such an equation in 1926, but found it in a form which did not offer useful information when it was solved.

Throughout his life, de Broglie was concerned with the philosophical issues of physics and he was the author of a number of books on this subject.