1899-1980

American physicist best known for his quantum explanation of magnetic phenomena. He introduced the concept of temperature-independent susceptibility known as Van Vleck paramagnetism and used quantum theory to evaluate the behavior of an atom or an ion in crystals. His work on electron correlation was exploited by others in developing the laser. Van Vleck shared the 1977 Nobel Prize in physics with Philip Anderson and Neville Mott for "investigations of the electronic structure of magnetic and disordered systems."