Michael A. Horne (January 18, 1943 – January 19, 2019) was an American quantum

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 ca ...

, famous for his work on the foundations of quantum mechanics.

Biography

Horne studied at the

University of Mississippi The University of Mississippi ( byname Ole Miss) is a public research university that is located adjacent to Oxford, Mississippi, and has a medical center in Jackson. It is Mississippi's oldest public university and its largest by enrollment. ...

and earned his doctorate in physics at

Boston University Boston University (BU) is a private research university in Boston, Massachusetts. The university is nonsectarian, but has a historical affiliation with the United Methodist Church. It was founded in 1839 by Methodists with its original c ...

with

Abner Shimony Abner Eliezer Shimony (; March 10, 1928 – August 8, 2015) was an American physicist and philosopher. He specialized in quantum theory and philosophy of science. As a physicist, he concentrated on the interaction between relativity theory and q ...

. He taught at

Stonehill College Stonehill College is a private Roman Catholic liberal arts college in Easton, Massachusetts. It was founded in 1948 by the Congregation of Holy Cross and is located on the original estate of Frederick Lothrop Ames Jr., with 29 buildings that co ...

, a catholic school in Easton in the south of

Boston Boston (), officially the City of Boston, is the capital city, state capital and List of municipalities in Massachusetts, most populous city of the Commonwealth (U.S. state), Commonwealth of Massachusetts, as well as the cultural and financ ...

. Together with

John Clauser 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 a ...

and Richard A. Holt he developed the

CHSH inequality In physics, the CHSH inequality can be used in the proof of Bell's theorem, which states that certain consequences of entanglement in quantum mechanics can not be reproduced by local hidden-variable theories. Experimental verification of the i ...

for experimentally testing Bell's theorem (the test was conducted in 1972 by John Clauser and

Stuart Freedman Stuart Jay Freedman (January 13, 1944 – November 10, 2012) was an American physicist, known for his work on a Bell test experiment with John Clauser at the University of California, Berkeley as well as for his contributions to nuclear and par ...

). In 1975 he started to investigate

neutron interferometry In physics, a neutron interferometer is an interferometer capable of diffracting neutrons, allowing the wave-like nature of neutrons, and other related phenomena, to be explored. Interferometry Interferometry inherently depends on the wave natu ...

in collaboration with

Clifford Shull Clifford Glenwood Shull (September 23, 1915 in Pittsburgh, Pennsylvania – March 31, 2001) was a Nobel Prize-winning American physicist. Biography Shull attended Schenley High School in Pittsburgh, received his BS from Carnegie Institute of Tec ...

at the MIT (at this time, neutron interference experiments were being developed by

Sam Werner Sam Werner (born December 3, 1995) is a former American soccer player who previously played for Sacramento Republic FC in the USL Championship. Career College Werner played four years of college soccer at Stanford University between 2014 an ...

at the

University of Missouri The University of Missouri (Mizzou, MU, or Missouri) is a public land-grant research university in Columbia, Missouri. It is Missouri's largest university and the flagship of the four-campus University of Missouri System. MU was founded ...

and by Helmut Rauch and

Anton Zeilinger Anton Zeilinger (; born 20 May 1945) is an Austrian quantum physicist and Nobel laureate in physics of 2022. Zeilinger is professor of physics emeritus at the University of Vienna and senior scientist at the Institute for Quantum Optics and Qu ...

at the

University of Vienna The University of Vienna (german: Universität Wien) is a public research university located in Vienna, Austria. It was founded by Duke Rudolph IV in 1365 and is the oldest university in the German-speaking world. With its long and rich h ...

). This led to an encounter with Daniel Greenberger, who had already theoretically proposed neutron interferometry for gravitation in the 1960s and was also interested in Shull's experiment, and later with Zeilinger (in Grenoble 1978). With Daniel Greenberger and Anton Zeilinger in 1989 he introduced

quantum entangled Quantum entanglement is the phenomenon that occurs when a group of particles are generated, interact, or share spatial proximity in a way such that the quantum state of each particle of the group cannot be described independently of the state of ...

states of three subsystems (

Greenberger–Horne–Zeilinger state In physics, in the area of quantum information theory, a Greenberger–Horne–Zeilinger state (GHZ state) is a certain type of entangled quantum state that involves at least three subsystems (particle states, qubits, or qudits). It was fir ...

s)., which was first experimentally realized in 1998Dik Bouwmeester,

Jian-Wei Pan Pan Jianwei (; born 11 March 1970) is a Chinese quantum physicist, university administrator and professor of physics at the University of Science and Technology of China. Pan is known for his work in the field of quantum entanglement, quantu ...

, Matthew Daniell, Harald Weinfurter, Anton Zeilinger: Observation of three-photon Greenberger-Horne-Zeilinger entanglement, Phys . Rev. Lett., Volume 82, 1999, pp. 1345–1349,

Arxiv arXiv (pronounced " archive"—the X represents the Greek letter chi ⟨χ⟩) is an open-access repository of electronic preprints and postprints (known as e-prints) approved for posting after moderation, but not peer review. It consists o ...

and represents a conceptual improvement over experiments based on Bell's inequality, as the violation with

local realism In physics, the principle of locality states that an object is influenced directly only by its immediate surroundings. A theory that includes the principle of locality is said to be a "local theory". This is an alternative to the concept of ins ...

was now a deterministic consequence predicted by quantum physics. GHZ states were the first examples of quantum entanglement with more than two particles and play a fundamental role in

quantum information theory Quantum information is the information of the state of a quantum system. It is the basic entity of study in quantum information theory, and can be manipulated using quantum information processing techniques. Quantum information refers to both ...

Selected works

* with J. Clauser, Abner Shimony, Richard Holt: Proposed experiment to test local hidden variable theories. In: Physical Review Letters. Band 23, 1969, S. 880. * with J. Clauser: Experimental consequences of objective local theories. In: Physical Review D. Band 10, 1974, S. 526

References

External links

Website at Stonehill College

Oral History Interview, AIP, 2002

Volume in Honor of Michael Horne by His Colleagues
{{DEFAULTSORT:Horne, Michael 21st-century American physicists 1946 births 2019 deaths Boston University alumni University of Mississippi alumni 20th-century American physicists People from Gulfport, Mississippi Quantum physicists