Walter Kohn

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Walter Kohn was an American theoretical chemist and theoretical physicist who was born in Austria. In 1998, he won the Nobel Prize in Chemistry for creating the density-functional theory. He shared the prize with kohn Pople, who also did computer work in quantum mechanics, but on his own. The density-functional theory that Kohn came up with helped include quantum mechanical effects in the density of electrons. Also, his theory put an end to the long-held belief that every electron’s movement could be tracked. Instead, he showed that the average number of electrons in space could be used as a measure. This helped scientists understand chemical structures and reactions better and gave them a new way to calculate them. It also made it easier to do the math needed to figure out how electrons connect atoms in molecules. Kohn was given many awards and honors during his life for his important contributions to science. He was a part of a lot of well-known scientific groups and institutions.

Early years and childhood

Walter Kohn was born to Salomon and Gittel Kohn on March 9, 1923, in Vienna, Austria. The Austrian Nazi regime was the first thing he could remember from his childhood.
Kohn went to a public elementary school when he was young. Later, he went to the Akademische Gymnasium, where he started to like Latin and Greek.

In 1938, when Hitler’s Germany took over Austria, the Kohns’ finances and reputation were hurt. Their family business was taken away, and their freedom was taken away. kohn was kicked out of his school. After that, he went to a Jewish school, where he learned to like math and science.

During World War II, Kohn’s parents were not able to leave Austria, so he was sent to England as part of the famous Kindertransport rescue operation. He was first taken to England, where he stayed with the Hauffs. Senior Kohn did business with the Hauffs. But because he was a German citizen, the British sent him to Canada. Dr. Bruno Mendel was his guardian in Canada.

He finally found a place to live at the camp in Trois-Rivières, Canada, for German prisoners of war and refugees. john was able to finish high school with the help of the camp’s educational facilities. He did well in school and passed the McGill University junior Matriculation exam as well as the senior matriculation math, physics, and chemistry tests.

Kohn did well enough to get into the University of Toronto. Since he wasn’t allowed in the building where chemistry was taught, he chose physics and math instead. In 1945, he got a BA in applied mathematics, and the next year, he got an MA in the same field.

Kohn got a Lehmann fellowship and went to Harvard, which is a very good school. He did his thesis work on the Green’s function variational method of three-body scattering problem with the help of Julian Schwinger. In 1948, Kohn had a big break when he found a simple way to explain the variational principle of scattering. In the same year, he got his Ph.D. in physics.

Walter Kohn’s Career

After he got his Ph.D., Kohn stayed at Harvard and worked as a researcher and teacher. He worked with Schwinger on quantum electrodynamics and the new field theory of strong interactions between nucleons and mesons for two years while sharing an office with Sidney Borowitz.

He was also influenced by Van Vleck and solid-state physics while he was at Harvard. Kohn even filled in for Vleck as a teacher of solid-state physics when Vleck was out of town. The job gave him the chance to learn more about a new area of physics that he didn’t know much about before.

In 1950, the National Research Council in Copenhagen gave him a fellowship. He also got a job at the Carnegie Institute of Technology at the same time. After asking for time off, he went to Copenhagen to finish his fellowship. He studied solid-state physics in Copenhagen. He taught the subject as a substitute teacher and did research on it with Res Jost.

He went to the Carnegie Institute of Technology in 1952. At Carnegie, he did a lot of his groundbreaking work on multiple scattering band structures, which is now called the KKR method. He also worked on the image of the metallic Fermi Surface in the phonon spectrum, the exponential localization of Wannier functions, and the nature of the insulating state.

In 1953, with help from Van Vleck, he got a summer job as W. Shockley’s assistant at Bell Labs. His project was about how high-energy electrons damage Si and Ge when they are exposed to radiation. This was important because semiconductor devices were just starting to be used in space at the time.

Bell Labs, which is the best place to do research in solid-state physics, became Kohn’s summer home, and he went there every year until 1966.

Because Kohn worked at Bell Labs, he learned about the physics of semiconductors. Together with Luttinger, he came up with new ideas in semiconductor physics. For example, he and Luttinger developed an effective Hamiltonian in the presence of magnetic fields, the first non-heuristic derivation of the Boltzmann transport equation for quantum mechanical particles, and the Luttinger-Kohn model of the semiconductor band structure.

In 1960, Kohn became the head of the Physics Department at the University of California, San Diego, which had just opened that year. In 1963, he started working on developing density functional theory while on sabbatical at the Ecole Normale Superieure in Paris.

Kohn wanted to know if the distribution of an alloy’s electronic density tells us everything about it or just some of it. This led him to discover that for a single particle, there is an explicit elementary relationship between the potential and the density of the ground state. He realized that the same density distribution could be caused by two different potentials with different ground states.

He laid the groundwork for a theory that said it wasn’t necessary to explain the movement of every single electron. Instead, one could look at how many electrons are in space on average. His discovery opened up new ways to figure out how chemical structures and reactions work.

Kohn and his friend Pierre Hohenberg came up with the Hohenberg Kohn (HK) variational principle, which explained what they had found. The two people put out the report with different estimates. Together with Lu Jeu Sham, the Hohenberg-Kohn theorem was made even better. The Kohn-Sham equations were made by Kohn and Sham. These equations have become the mainstay of modern materials science and are even used in quantum theories of plasmas.

Kohn worked at the University of California, San Diego until 1979. After that, he became the first director of the new Institute for Theoretical Physics at the National Science Foundation in Santa Barbara. In it, he kept working on DFT with post-doctoral fellows.

Kohn became a professor in the Physics Department at the University of California at Santa Barbara in 1984. He kept working there until the day he died.

Works of note

The most important thing that Kohn did was come up with the density-functional theory. Throughout his career, he used quantum mechanics to figure out how atoms stick together with electric bonds to make molecules. In 1964, he laid the groundwork for a theory that said it was not necessary to explain the movement of every single electron.

Instead, one could look at how many electrons are in space on average. This helped scientists understand chemical structures and reactions better and gave them a new way to calculate them. It also made it easier to do the math needed to figure out how electrons connect atoms in molecules.

Awards & Achievements

The Oliver E. Buckley Prize and the Davison Germer Prize were given to him by the American Physical Society for his work in the field of semiconductor physics. The Feenberg Medal was also given to him.
He was given the National Medal of Science in 1988.

Kohn won the prestigious Nobel Prize in Chemistry in 1998 for creating the “density-functional theory.” He and john Pople both got the prize.

Austria gave him the Austria Decoration for Science and Art award and the Grand Decoration of Honor in Silver with Star for Services to the Republic of Austria.
Both the University of Oxford and Harvard University gave him an honorary doctorate.

He was chosen to be a member of the Royal Society from outside the UK. He also joined the American Academy of Arts and Sciences, the National Academy of Sciences, and the International Academy of Quantum Molecular Science. He joined the Austrian Academy of Sciences as a member of honor.

Personal History and Legacies

Kohn was married twice in his life. Lois Adams was his first wife, and then he married Mara Schiff.
On April 19, 2016, at the age of 93, he died of jaw cancer.

Estimated Net worth

Walter is one of the wealthiest and most well-known physicists. Based on what we found on Wikipedia, Forbes, and Business Insider, Walter Kohn has a net worth of about $5 million.