约翰·克劳泽1942—

他与阿兰·阿斯佩和安东·蔡林格共同获得2022年诺贝尔物理学奖，表彰其“在有关量子纠缠的实验，确立贝尔不等式的违背验证以及开拓量子资讯科学”。

生平

克劳泽于1942年12月1日出生于加利福尼亚州帕萨迪纳。他于1964年获得加州理工学院的物理学学士学位，并于1966年获得物理学硕士学位，1969年在哥伦比亚大学获得物理学博士学位，师从帕特里克·撒迪厄斯。

1969年至1996年，他主要在劳伦斯伯克利国家实验室、劳伦斯利弗莫尔国家实验室和加利福尼亚大学伯克利分校工作。1972年，他与斯图尔特·弗里德曼合作，对CHSH-贝尔定理的预测进行首次实验测试。这是对违反贝尔不等式的第一次实验观察。

1974年，他与迈克尔·霍恩合作，首次表明贝尔定理的一般化为所有自然界的局部现实主义理论（又称客观局部理论）提供严格的约束。这项工作引入克劳泽-霍恩不等式，作为本地现实主义所设定的第一个完全通用的实验要求。它还引入了“CH无增强假设”，从而使CH不等式简化为CHSH不等式，并使相关的实验测试也约束局部现实主义。同样在1974年，他首次观察到光的亚泊松统计（通过违反经典电磁场的柯西-施瓦茨不等式），从而首次证明光子明确的粒子状特征。1976年，他对CHSH-贝尔定理的预测进行世界上第二次实验测试。

克劳泽与阿兰·阿斯佩和安东·蔡林格一起获得2010年的沃尔夫物理学奖。这三人还共同获得2022年的诺贝尔物理学奖。

John Francis Clauser (; born December 1, 1942) is an American theoretical and experimental physicist known for contributions to the foundations of quantum mechanics, in particular the Clauser–Horne–Shimony–Holt inequality. Clauser was awarded the 2022 Nobel Prize in Physics, jointly with Alain Aspect and Anton Zeilinger "for experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science". In 2023, he declared himself as a climate change denier.

Early life

Clauser was born in Pasadena, California. His father, Francis H. Clauser, was a professor of aeronautical engineering who founded and chaired the aeronautics department at Johns Hopkins University. He later served as the Clark Blanchard Millikan Professor of Engineering at the California Institute of Technology (Caltech). His mother, Catharine McMillan, was the humanities librarian at Caltech and sister of 1951 Nobel Prize in Chemistry laureate Edwin McMillan.

He received a Bachelor of Science in physics from Caltech in 1964, where he was a member of Dabney House. He received a Master of Arts in physics in 1966 and a Doctor of Philosophy in physics in 1969 from Columbia University under the direction of Patrick Thaddeus.

Career

From 1969 to 1975, he worked as a postdoctoral researcher at the University of California, Berkeley and Lawrence Berkeley National Laboratory. In 1972, working with Berkeley graduate student Stuart Freedman, he carried out the first experimental test of the CHSH-Bell's theorem predictions. This was the first experimental observation of a violation of a Bell inequality. In 1974, working with Michael Horne, he first showed that a generalization of Bell's Theorem provides severe constraints for all local realistic theories of nature (a.k.a. objective local theories). That work introduced the Clauser–Horne (CH) inequality as the first fully general experimental requirement set by local realism. It also introduced the "CH no-enhancement assumption", whereupon the CH inequality reduces to the CHSH inequality, and whereupon associated experimental tests also constrain local realism. Also in 1974 he made the first observation of sub-Poissonian statistics for light (via a violation of the Cauchy–Schwarz inequality for classical electromagnetic fields), and thereby, for the first time, demonstrated an unambiguous particle-like character for photons.

Starting in 1973, Clauser published the newsletter Epistemological Letters, which was created because mainstream academic journals were relunctant to publish articles about the philosophy of quantum mechanics. Clauser worked as a research physicist mainly at Lawrence Livermore and Berkeley from 1975 to 1997. In 1976 he carried out the world's second experimental test of the CHSH-Bell's Theorem predictions.

Clauser was awarded the Wolf Prize in Physics in 2010 together with Alain Aspect and Anton Zeilinger. The three were also jointly awarded the 2022 Nobel Prize in Physics.

Climate change denial

In May 2023, Clauser joined the board of the CO2 Coalition, a climate change denial organization. Later that year, Clauser called himself a "climate denier" and claimed "there is no climate crisis". Clauser's views on climate change have been described as "pseudoscience". His belief that cloud cover has more of an impact on Earth's temperature than carbon dioxide emissions is contradicted by the overwhelming scientific consensus on climate change.

Personal life

Clauser is an atheist. He has emphysema due to smoking cigarettes in his youth.