H. Dieter Zeh

{{Infobox scientist

| name = H. Dieter Zeh

| image = DieterZeh2005-09-17-14-39-36.jpg

| image_size =

| image_upright =

| alt =

| caption =

| birth_date = {{birth date |1932|5|8|df=yes}}

| birth_place = Braunschweig, Free State of Brunswick

| death_date = {{death date and age |2018|4|15 |1932|5|8|df=yes}}

| death_place = Freudenstadt, Baden-Württemberg

| fields = Theoretical physics

| workplaces = University of Heidelberg

| education = Technical University of Braunschweig
University of Heidelberg

| alma_mater =

| thesis_title = Untersuchungen zur Theorie des $\alpha$ -Zerfalls

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| thesis_year = 1961

| doctoral_advisor = {{ill| Hans Jörg Mang|de}}

| doctoral_students =

| known_for = Many-minds interpretation
Quantum decoherence

| awards =

}}

Heinz-Dieter Zeh ({{IPA|de|tseː|lang}}; 8 May 1932 – 15 April 2018) was theoretical physicist and professor emeritus of the University of Heidelberg. He is known for formalizing the theory of quantum decoherence.

Education and career

H. Dieter Zeh was born in Braunschweig and studied physics at the Technical University of Braunschweig and nuclear physics at the University of Heidelberg under J. Hans D. Jensen. At Heidelberg, he also investigated alpha particle formation in nuclei with {{Ill|Hans Jörg Mang|de}} and Zeh investigated the topic for his PhD thesis under Mang. Between 1964 and 1965, Zeh was a research assistant at California Institute of Technology and in 1965 and between 1967 and 1968 at the University of California, San Diego. He later became a professor in Heidelberg.{{Cite web |last=Päs |first=Heinrich |date=2018-05-16 |title=Der Alte Mann und das Multiversum - Ein Nachruf auf H. Dieter Zeh |url=https://scilogs.spektrum.de/das-zauberwort/der-alte-mann-und-das-multiversum-ein-nachruf-auf-h-dieter-zeh/ |access-date=2023-09-10 |website=Das Zauberwort |language=de-DE}}{{Cite journal |last=Kiefer |first=Claus |journal=International Journal of Quantum Foundations |date=2018-12-29 |title=OBITUARY FOR HEINZ-DIETER ZEH (1932 — 2018) |url=https://ijqf.org/archives/5309 |access-date=2023-09-10 |language=en-US}}

Research

Zeh is known for his work on decoherence, formally described in his 1970 seminal paper.{{Cite journal |last=Zeh |first=H. D. |date=1970 |title=On the interpretation of measurement in quantum theory |url=http://link.springer.com/10.1007/BF00708656 |journal=Foundations of Physics |language=en |volume=1 |issue=1 |pages=69–76 |bibcode=1970FoPh....1...69Z |doi=10.1007/BF00708656 |issn=0015-9018}} He showed that the environment plays a central role in recovering the classical limit from quantum mechanics. In his paper he discussed applications, like explaining the emergence of chirality in sugar molecules. In 1973, with Olaf Kübler, Zeh explained using a reduced density matrix why coherent state are the most classical states, and why quantum superposition can never be observed. Zeh's works provided a solution to the preferred basis problem in quantum mechanics.

The term decoherence did not appear until 1989. The first experimental demonstrations of Zeh's work were given about 1996 by Serge Haroche in France and David J. Wineland in United States, who also earned the 2012 Nobel Prize in Physics.

Zeh's 1970 work was also one of the founding papers of the many-minds interpretation of quantum mechanics.{{Cite journal |last=Lockwood |first=Michael |date=1996 |title='Many Minds'. Interpretations of Quantum Mechanics |url=https://www.jstor.org/stable/687940 |journal=The British Journal for the Philosophy of Science |volume=47 |issue=2 |pages=159–188 |doi=10.1093/bjps/47.2.159 |jstor=687940 |issn=0007-0882}}

Zeh also dedicated a large part of his work to quantum gravity. In 1986, he argued that gravity assumes classical properties due to environmental degrees of freedom, such as the presence of gravitational waves.

Bibliography

The Problem Of Conscious Observation In Quantum Mechanical Description (June, 2000).
The Physical Basis of the Direction of Time, 2001, {{ISBN|3-540-42081-9}}
Decoherence and the Appearance of a Classical World in Quantum Theory, 2003, {{ISBN|3-540-00390-8}} (with Erich Joos, Claus Kiefer, Domenico Giulini, Joachim Kupsch, Ion-Olimpiu Stamatescu)
"On the interpretation of measurement in quantum theory", 1970, Foundations of Physics, Volume 1, Issue 1, pp. 69–76