Michael Tinkham (February 23, 1928 – November 4, 2010) was an American physicist. He was Rumford Professor of Physics and Gordon McKay Research Professor of Applied Physics at

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of high ...

. He is best known for his work on superconductivity.

Professional life

Tinkham was born and raised in Brooklyn Township, a farming community in

Green Lake County, Wisconsin Green Lake County is a county located in the U.S. state of Wisconsin. As of the 2020 census, the population was 19,018. Its county seat is Green Lake. In 2020, the center of population of Wisconsin was located in Green Lake County, near the c ...

. He studied nearby at Ripon College in Wisconsin, where he obtained a BA in 1951. He continued at the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...

, achieving a Master's in 1951, followed by a PhD in 1954. During 1954–55 he worked in the

Clarendon Laboratory The Clarendon Laboratory, located on Parks Road within the Science Area in Oxford, England (not to be confused with the Clarendon Building, also in Oxford), is part of the Department of Physics at Oxford University. It houses the atomic and ...

at the

University of Oxford , mottoeng = The Lord is my light , established = , endowment = £6.1 billion (including colleges) (2019) , budget = £2.145 billion (2019–20) , chancellor ...

. In 1955 he moved to the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant u ...

, in becoming an assistant professor in 1957, with a full professorship laler. In 1966 he joined the faculty at Harvard University as full professor. During 1978–79 he was a Humboldt U.S. Senior Scientist at the

University of Karlsruhe The Karlsruhe Institute of Technology (KIT; german: Karlsruher Institut für Technologie) is a public research university in Karlsruhe, Germany. The institute is a national research center of the Helmholtz Association. KIT was created in 2009 w ...

. Tinkham's research concentrated on superconductivity and in 1975 he published one of the classic textbooks on the subject. Later he focused on material properties where sample dimensions are in the nanometer range, including studies of nanowires and carbon nanotubes. In 1970 Tinkham was made a member of the National Academy of Sciences, and in 1974 was awarded the Oliver E. Buckley Condensed Matter Prize. He received the Fred E. Saalfeld Award for Outstanding Lifetime Achievement in Science in 2005. He has also been honored for his achievements by his colleagues in the Journal of Superconductivity. Tinkham maintained an active research group at

until his retirement. Over these years, he trained over 45 students who received their PhDs under his guidance.

Work on superconductivity

In 1956, Tinkham and a fellow postdoc Rolfe Glover found the direct evidence of an

energy gap In solid-state physics, an energy gap is an energy range in a solid where no electron states exist, i.e. an energy range where the density of states vanishes. Especially in condensed-matter physics, an energy gap is often known more abstractly as ...

in the continuous distribution of energy levels in the form of a sharp rise in the optical absorption spectrum of a superconductor. The absorption spectrum observed was a direct consequence of the coherence factors of

BCS theory BCS theory or Bardeen–Cooper–Schrieffer theory (named after John Bardeen, Leon Cooper, and John Robert Schrieffer) is the first microscopic theory of superconductivity since Heike Kamerlingh Onnes's 1911 discovery. The theory describes sup ...

due to John Bardeen,

Leon Cooper Leon N Cooper (born February 28, 1930) is an American physicist and Nobel Prize laureate who, with John Bardeen and John Robert Schrieffer, developed the BCS theory of superconductivity. His name is also associated with the Cooper pair and co-deve ...

, and

John Robert Schrieffer John Robert Schrieffer (; May 31, 1931 – July 27, 2019) was an American physicist who, with John Bardeen and Leon Cooper, was a recipient of the 1972 Nobel Prize in Physics for developing the BCS theory, the first successful quantum theor ...

; along with other observations, it provided the first substantive experimental confirmation of BCS theory. Tinkham also studied the macroscopic quantum behaviour of superconductors, and examined the conditions under which transitions between different energy levels happen when superconductors are carrying a current.

References

1928 births 2010 deaths American physicists Massachusetts Institute of Technology alumni Harvard University faculty Ripon College (Wisconsin) alumni Members of the United States National Academy of Sciences Oliver E. Buckley Condensed Matter Prize winners {{US-physicist-stub