Brian Pippard

Brian Pippard. Sir Alfred Brian Pippard was a distinguished British physicist whose pioneering work in condensed matter physics, particularly on the electrodynamics of superconductors and metals, shaped the modern understanding of these materials. A long-time professor at the University of Cambridge and head of the famed Cavendish Laboratory, he was instrumental in bridging the gap between the microscopic BCS theory and macroscopic electromagnetic phenomena. His concepts, such as the Pippard coherence length and the non-local electrodynamics of superconductors, remain foundational in the field.

Early life and education

Born in London, he was the son of Alfred Pippard, a noted professor of civil engineering. He attended Clifton College in Bristol before entering Clare College, Cambridge in 1939 to study Natural Sciences. His undergraduate studies at the University of Cambridge were interrupted by service in the Second World War, where he worked on radar development at the Telecommunications Research Establishment. After the war, he returned to Cambridge to complete his degree and commenced doctoral research under the supervision of David Shoenberg at the Cavendish Laboratory, investigating the surface impedance of metals at high frequencies.

Career and research

Pippard spent his entire academic career at the University of Cambridge. He was appointed a lecturer in physics in 1950, a fellow of Clare College, Cambridge in 1951, and later became the John Humphrey Plummer Professor of Physics in 1960. His most influential tenure was as head of the Cavendish Laboratory from 1971 until his retirement in 1982, where he oversaw a period of significant expansion and modernization. His research focused intensely on the properties of metals and superconductors, where he developed the concept of non-local electrodynamics to explain the anomalous skin effect. This work directly led to his formulation of the Pippard coherence length, a critical parameter describing the range over which the superconducting order parameter varies.

Pippard's scientific contributions

Pippard's key contribution was his phenomenological theory of superconductivity, which preceded and informed the fully microscopic BCS theory developed by John Bardeen, Leon Cooper, and John Robert Schrieffer. He introduced the idea that a superconductor's response to an electromagnetic field is non-local, meaning it depends on the field over a finite distance, now known as the Pippard coherence length. This was encapsulated in the Pippard kernel, which modified the simpler London equations. He also established the Pippard relations linking penetration depth, coherence length, and critical field. His early work on the anomalous skin effect in normal metals provided crucial experimental evidence for the Fermi surface concept, greatly advancing the field of solid-state physics.

Awards and honours

Pippard received numerous accolades for his scientific work. He was elected a Fellow of the Royal Society in 1956. He was awarded the Hughes Medal of the Royal Society in 1959 for his studies of the dynamics of conduction electrons. In 1975, he was knighted for his services to science. He received the prestigious Royal Medal from the Royal Society in 1995. He also held honorary degrees from several universities, including the University of Bristol and the University of Leeds, and was an honorary fellow of Clare College, Cambridge.

Personal life

He married (Margaret) Elizabeth Galleymore in 1953, and they had two sons. Known for his intellectual rigour and clarity, he was also an accomplished pianist with a deep love for music. After retiring from the Cavendish Laboratory, he remained active in writing and served as a visiting professor at institutions like Brown University. He passed away in Cambridge in 2008. His legacy endures through his influential textbooks, such as *The Dynamics of Conduction Electrons*, and the fundamental concepts that bear his name in the study of condensed matter physics.

Category:British physicists Category:Fellows of the Royal Society Category:University of Cambridge faculty Category:Alumni of Clare College, Cambridge Category:1920 births Category:2008 deaths