Michael Dudley Sturge

Abstract

Michael Dudley Sturge, best known for his contributions to solid-state spectroscopy, died of leukemia on 13 July 2003 in Castleton, England.Born on 25 May 1931 in Bristol, England, Michael obtained his BA in engineering and physics (1952) and his PhD in physics (1957) at Cambridge University, where he worked on superconductors under Brian Pippard. After two years at Philips Labs outside London, Michael moved to the Royal Radar Establishment in Malvern, where he published, in Physical Review, his paper on the spectroscopy of gallium arsenide. That work included GaAs band structure parameters (most timely for the GaAs laser, invented in the same year) and the first observation of Wannier–Mott excitons in a III–V semiconductor. The paper became a citation classic and brought him international recognition.In 1961, Michael joined Bell Labs in Murray Hill, New Jersey. During his more than 20 years as a member of the technical staff, he grew into one of the leading experts on the optical properties of semiconductors and commanded a tremendous level of respect within that highly skilled community. His expertise, intense level of scientific curiosity, and personal and scientific integrity attracted many young scientists to Bell Labs, and he became a cherished mentor to many of them.In 1984, Michael joined Bell Communication Research in Murray Hill, an R&D firm that had split from Bell Labs. Two years later, he became a professor of physics at Dartmouth College.Michael first worked on the spec-troscopy of transition-metal ions in crystals, basic solid-state laser materials. By combining optical and electron paramagnetic resonance spectro-scopies, he identified the role of the dynamic Jahn–Teller effect in ion-level splitting and the collective Jahn–Teller effect in phase transitions of rare-earth perovskites. In the mid-1970s, Michael returned to the fundamental optical properties of semiconductors. He studied the excited states of excitons bound to isoelectronic nitrogen pairs in bulk gallium phosphide and classified them using the model of a tightly trapped electron and a hole orbiting the pair. When the interest of the semiconductor community turned to quantum wells and superlattices, he studied transport and cyclotron resonance in two-dimensional electron systems and participated in the discovery of minigaps in metal-oxide-semiconductor field effects and in the initial experiments on modulation-doped superlattices. In the early 1980s, Michael made important contributions to the spectroscopy of disordered semiconductor systems. By combining experiments of luminescence, resonant Rayleigh scattering, hole burning, and transient grating spectroscopy, he found clear evidence for a mobility gap in the spectrum of excitons in quantum wells. He also discovered a new type of exciton in short-period superlattices, which is indirect in both real and reciprocal spaces, and electric-field controlled switching between the direct and indirect band structures. Michael’s last work was on trions, complexes of a hole and two electrons similar to H− ions. He discovered a puzzling abrupt changeover in the magnetoluminescence from free-particle to bound-particle behavior when the lower electron Landau level becomes just filled. That observation proved that a “hidden symmetry,” known for strong magnetic fields, surprisingly manifests itself in moderate-to-weak fields.Michael always set the highest standards for his work. He perceived science in its unity and applied that approach when composing, with one of us (Rashba), the volume Excitons (North-Holland, 1982), which included reviews of excitons. As the general editor of the Journal of Luminescence from 1985 to 1990, Michael expanded its scope to embrace modern research areas. At Dartmouth, he brought the same standards to his teaching, which he continued after retiring from the college in 1998. To introduce students to the dramatic history of physics during the 20th century, Michael worked with them on factual and moral problems raised by Michael Frayn’s play Copenhagen. He also wrote a textbook on statistical physics that included many recently studied systems.To honor Michael’s scientific achievements and his leadership, the International Conference on Dynamical Processes in Excited States of Solids has established the Sturge Prize for outstanding contributions to solid-state spectroscopy made by young scientists. The prize will be awarded for the first time in 2005.Michael enjoyed sailing and hiking and had a deep knowledge of history, politics, and philosophy. When visiting Jerusalem in 1972, Michael, in a quiet and almost shy way, kept correcting the old professional guide about historical facts. In 1987, at the Triniti-Sergey Monastery museum near Moscow, Michael noticed that an exhibit designated as “A prayer book of the Czar Ivan the Terrible” was actually published after Ivan’s death. The astonished guide explained that the original book was lost, and Michael was the first visitor to notice the inconsistency. Michael commented that it was merely his professional habit to pay attention to details and notice anomalies.Michael was a prominent researcher and a person of extraordinary standards and integrity. His family, colleagues, and friends will miss him.Michael Dudley SturgePPT|High resolution© 2004 American Institute of Physics.