Maurice Kleman (alternate spelling Kléman; 11 August 1934 – 29 January 2021) was a French

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

involved in experimental and theoretical studies of the physics of defects; he has covered various fields of research, from

condensed matter Condensed matter physics is the field of physics that deals with the macroscopic and microscopic physical properties of matter, especially the solid and liquid phases, that arise from electromagnetic forces between atoms and electrons. More gen ...

heliophysics Heliophysics (from the prefix "wikt:helio-, helio", from Attic Greek ''hḗlios'', meaning Sun, and the noun "physics": the science of matter and energy and their interactions) is the physics of the Sun and its connection with the Solar System. ...

. As an author, he has been collected by libraries worldwide.

Early life

Kleman was born in

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...

in a family of Jewish origin which was saved from the Nazi persecutions during the

Second World War World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

by the inhabitants of the village of

Le Chambon-sur-Lignon Le Chambon-sur-Lignon (, literally "Le Chambon on Lignon"; ) is a commune in the Haute-Loire department in south-central France. Residents have been primarily Huguenot or Protestant since the 17th century. During World War II these Huguenot ...

Haute-Loire Haute-Loire (; or ''Naut Leir''; English: Upper Loire) is a landlocked department in the Auvergne-Rhône-Alpes region of south-central France. Named after the Loire River, it is surrounded by the departments of Loire, Ardèche, Lozère, Canta ...

, as many other refugees were; this village is collectively honored as

Righteous Among the Nations Righteous Among the Nations ( ) is a title used by Yad Vashem to describe people who, for various reasons, made an effort to assist victims, mostly Jews, who were being persecuted and exterminated by Nazi Germany, Fascist Romania, Fascist Italy, ...

Education

Ecole Polytechnique and Ecole des Mines de Paris; PhD under J. Friedel’s supervision on

ferromagnetic Ferromagnetism is a property of certain materials (such as iron) that results in a significant, observable magnetic permeability, and in many cases, a significant magnetic coercivity, allowing the material to form a permanent magnet. Ferromagne ...

thin films, at the French Iron and Steel Institute (IRSID). Postdoc at the

University of Oxford The University of Oxford is a collegiate university, collegiate research university in Oxford, England. There is evidence of teaching as early as 1096, making it the oldest university in the English-speaking world and the List of oldest un ...

Career

Kleman belonged to the

Centre National de la Recherche Scientifique The French National Centre for Scientific Research (, , CNRS) is the French state research organisation and is the largest fundamental science agency in Europe. In 2016, it employed 31,637 staff, including 11,137 tenured researchers, 13,415 eng ...

(CNRS) since 1969, first as a member of the Laboratoire de Physique des Solides (LPS) in

Orsay Orsay () is a Communes of France, commune in the Essonne Departments of France, department in Île-de-France in northern France. It is located in the southwestern suburbs of Paris, France, from the Kilometre Zero, centre of Paris. A fortifie ...

(1969-1993), which he headed from 1982 to 1984, then of the Laboratoire de Minéralogie et de Cristallographie de Paris (LMCP). He joined the

Institut de Physique du Globe de Paris The Institut de Physique du Globe de Paris (, ; abbr. IPGP) is a French governmental, non-profit research and higher education establishment located in Paris, dedicated to the study of earth and planetary sciences by combining observations, labora ...

(IPGP) in 2010 and has been visiting professor at the Ecole polytechnique fédérale de Lausanne and at the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a Private university, private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of moder ...

(MIT).

Research

Kleman’s research covers many domains, in

materials science Materials science is an interdisciplinary field of researching and discovering materials. Materials engineering is an engineering field of finding uses for materials in other fields and industries. The intellectual origins of materials sci ...

(

liquid crystals Liquid crystal (LC) is a state of matter whose properties are between those of conventional liquids and those of solid crystals. For example, a liquid crystal can flow like a liquid, but its molecules may be oriented in a common direction as i ...

quasicrystals A quasiperiodicity, quasiperiodic crystal, or quasicrystal, is a structure that is Order and disorder (physics), ordered but not Bravais lattice, periodic. A quasicrystalline pattern can continuously fill all available space, but it lacks trans ...

, magnetic systems, amorphous media), more recently in

(magnetic flux ropes). In all these domains his interests are concerned with the concept of defect, in the continuation of F.C. Frank and J. Friedel. He demonstrated the role of curved crystal defects in the topology of frustrated systems. He developed with J. Friedel the concepts of continuous defects. He showed that interplanetary magnetic flux ropes can be understood as extended singularities of the vector potential.

Awards

* 1975: Médaille d'argent du CNRS * 1980: Prix de Physique Jean Ricard de la Société Française de Physique * 2007: Grand Prix de l’Académie des Sciences (prix du CEA) * 2018: International Honorary Member of the American Academy of Arts and Sciences.

Books

* * *

References

{{DEFAULTSORT:Kleman, Maurice 1934 births 2021 deaths 20th-century French Jews 21st-century French Jews École Polytechnique alumni Mines Paris - PSL alumni French physicists French science writers Writers from Paris