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Wander Johannes de Haas –

Top 10 Fascinating Facts about Wander Johannes de Haas

Wander Johannes de Haas was a Dutch physicist and mathematician. Wander was the son of a schoolmaster. After finishing high school in 1895 he first started to read for the examinations for notary public, but after having passed two of the required three and after having worked for a short period in a notary’s office, he decided that this career was not to his taste and he went to Leiden to study physics. 

Wander Johannes was assistant to Kamerlingh Onnes from 1905 to 1911, and in 1912 he obtained his doctorate’s degree with the thesis: “Measurements Concerning the Compressibility of Hydrogen, in Particular of Hydrogen Vapor at and below the Boiling Point”.

Here are the top 10 fascinating facts about Wander Johannes de Haas.

1. Wander is best known for the Shubnikov–de Haas effect

An oscillation in the conductivity of a material that occurs at low temperatures in the presence of very intense magnetic fields, the Shubnikov–de Haas effect (SdH) is a macroscopic manifestation of the inherently quantum mechanical nature of matter. 

It is often used to determine the effective mass of charge carriers (electrons and electron holes), allowing investigators to distinguish between majority and minority carrier populations. The effect is named after Wander Johannes de Haas and Lev Shubnikov.

2. Wander de Haas was born in a small town called Lisse

Lisse, Netherlands –

Wander was the son of Albertus de Haas, principal of the Teacher’s College in Middelburg, and Maria Efting.

Lisse is a town and municipality in the province of South Holland in the Western Netherlands. 

3. Wander started off as a Lawyer before switching careers

After attending high school in Middelburg, De Haas started paralegal studies in 1895. 

After completing two of three parts of examinations and having worked in a lawyer’s office for some time, he decided to change career and become a physicist instead.

4. Wander started to study physics at the University of Leiden 

University of Leiden by Rudolphous –

After passing the qualifications exams for admission to University, he started to study physics at the University of Leiden in 1900 under Heike Kamerlingh Onnes and Johannes Petrus Kuenen. He earned his doctorate in 1912, under Kamerlingh Onnes, with a thesis entitled: Measurements on the Compressibility of Hydrogen.

Physics is the natural science that studies matter, its fundamental constituents, its motion and behaviour through space and time, and the related entities of energy and force. Physics is one of the most fundamental scientific disciplines, with its main goal being to understand how the universe behaves. A scientist who specializes in the field of physics is called a physicist.

5. Wander is also known for the De Haas–Van Alphen effect

The De Haas–Van Alphen effect, often abbreviated to DHVA, is a quantum mechanical effect in which the magnetic susceptibility of a pure metal crystal oscillates as the intensity of the magnetic field B is increased. 

The DHVA effect comes from the orbital motion of itinerant electrons in the material.  It can be used to determine the Fermi surface of a material. Other quantities also oscillate, such as the electrical resistivity, specific heat, and sound attenuation and speed. It is named after Wander Johannes de Haas and his student Pieter M. van Alphen.

6. De Haas worked in Berlin as a researcher at the Physikalische Reichsanstalt

Physikalisch-Technische Bundesanstalt by Axel Hindemith –

The Physikalisch-Technische Bundesanstalt (PTB) is the national metrology institute of the Federal Republic of Germany, with scientific and technical service tasks. It is a higher federal authority and a public-law institution directly under federal government control, without legal capacity, under the auspices of the Federal Ministry for Economic Affairs and Energy.

7. Wander returned to the Netherlands and taught at various institutions

De Haas returned to the Netherlands, worked as a schoolteacher in Deventer, a conservator of the Teylers Museum in Haarlem, and then a physics professor at Delft Technical School and the University of Groningen. 

In 1925, he became a professor in Leiden, and one of the two heads of the Laboratory of Physics, succeeding Kamerlingh Onnes. In 1948, De Haas retired.

8. In 1922, De Haas became a member of the Royal Netherlands Academy of Arts and Sciences

Wander Johannes de Haas in 1924 –

The Royal Netherlands Academy of Arts and Sciences is an organization dedicated to the advancement of science and literature in the Netherlands. Twenty years later, in 1942, he was forced to resign. After World War II ended in 1945, he was allowed to rejoin as a member.

In addition to various advisory and administrative functions, it operates a number of research institutes and awards many prizes, including the Lorentz Medal in theoretical physics, the Dr Hendrik Muller Prize for Behavioural and Social Science and the Heineken Prizes.

9. Wander pointed out a correlation between diamagnetism and change of resistance in a magnetic field

As early as 1914 De Haas had pointed out that there might be a correlation between diamagnetism and change of resistance in a magnetic field, so it is not surprising that after the spectacular results of Shubnikov he suggested to one of his students, P.M. van Alphen that he should investigate the diamagnetism of bismuth at low temperatures. 

That hunch yielded rich rewards. It was found that the diamagnetic susceptibility of bismuth at low temperatures is not constant but shows periodic variations as a function of the magnetic field. That is the famous De Haas-Van Alphen effect that later in the hands of Schoenberg and others became an important tool for finding details of the states of electrons in metals.

10. Wander contributed to the Einstein-De Haas effect

Solvay conference in 1930 by Benjamin Couprie –

The Einstein–de Haas effect is a physical phenomenon in which a change in the magnetic moment of a free body causes this body to rotate. The effect is a consequence of the conservation of angular momentum.

The effect was predicted by O. W. Richardson in 1908. It is named after Albert Einstein and Wander Johannes de Haas, who published two papers in 1915 claiming the first experimental observation of the effect.