Wander Johannes de Haas (21.03.1878-26.04.1960) was a Dutch physicist and a member of the Royal Netherlands Academy of Arts and Sciences (1922). He was born in Lisse. In 1895-1917 he worked in Leiden, Berlin and Potsdam and at Teylers Museum in Haarlem; in 1917—22 he was professor at the Higher Technical School in Delft, in 1922—24 at the University of Groningen, and in 1924—48 professor at the University of Leiden and director of the H. Kamerlingh Onnes cryogenic laboratory.
His research concerned low-temperature physics and superconductivity. He studied effects at low temperatures and the superconductivity of magnetic materials, and reached a record low temperature of 0.0002 K. In 1915, together with A. Einstein, he detected experimentally and explained theoretically the phenomenon that, when a body is magnetised along some axis, it acquires about that axis an angular momentum proportional to the magnetisation (the Einstein-de Haas effect). In 1930, together with L. V. Shubnikov, he discovered at low temperatures the dependence of the electrical resistance of bismuth on the reciprocal of the magnetic field (the Shubnikov-de Haas effect), and in 1931, with P. van Alphen, the dependence of the magnetic susceptibility of metals on the magnetic field strength (the de Haas-van Alphen effect).
The B. Rumford Medal (1934).