Boris Petrovich Zakharchenya, who made substantial contributions to modern condensed matter physics, died on 10 April 2005 in St. Petersburg, Russia, after a courageous yearlong fight against cancer.
Born in Orsha, Belarus, on 1 May 1928, Boris learned to read by the time he was two years old. His family moved to Leningrad (now St. Petersburg) in the mid-1930s. In 1947, Boris entered Leningrad State University to study physics. After graduating in 1952, he was offered a postgraduate position at the A. F. Ioffe Physico-Technical Institute (PTI) in St. Petersburg, where he remained for the rest of his career.
He started his work at the Laboratory of Optics, then headed by eminent spectroscopist Evgeny Fedorovich Gross, and began intensive spectroscopic investigations on cuprous oxide (Cu 2O) crystals. A year before, in 1951, Gross and Nuri Karryev had discovered a hydrogen-like series of narrow lines in the absorption spectrum of that crystal and interpreted it as the spectrum of the exciton. In 1954 Boris observed the Stark effect and ionization of excitons in weak external electric fields, and thus confirmed the existence of Rydberg states in crystals. That same year he demonstrated for the first time the Zeeman splitting of exciton lines. In 1955 he discovered in Cu 2O crystals a gigantic diamagnetic shift of large-radius excitons’ excited states. Those experiments bore out the model of so-called Wannier—Mott excitons and marked the beginning of low-temperature spectroscopy of semiconductors. Also in 1955 Boris obtained a candidate’s degree with his thesis “Study on the Spectrum of Exciton Absorption of Light in the Cu 2O Crystal,” which he completed under Gross’s guidance.
Continuing with experiments on the gigantic diamagnetic shift in Cu 2O, in 1957 Boris was the first to discover, beyond the exciton series, oscillations of the absorption coefficient due to the appearance of Landau levels. Those investigations and independent observations by others of the same phenomenon in germanium and in indium antimonide marked the beginning of modern semiconductor magneto-optics. In the 1960s Boris and his postgraduate student Ruben Seisyan proved that in Ge and other crystals, the application of strong magnetic fields always leads to observation of quasi-one-dimensional diamagnetic excitons connected with interband optical transitions between Landau subbands. In 1961, practically simultaneously with David G. Thomas and John J. Hopfield at Bell Laboratories, Boris observed what is now known as the inversion effect. In 1966 he received the degree of Doctor of Physical-Mathematical Sciences for his thesis “Magneto-Optical Phenomena in Crystals.”
Soon Boris created his own laboratory and, in the 1970s, initiated and headed research on the optical orientation of electronic and nuclear spins in crystals when the spins were pumped by circularly polarized light. Boris and his team discovered a number of new phenomena important for understanding electronic and electron—nuclear spin processes in semiconductors, including deep optical cooling (down to 10−7 K) of nuclear spin systems and multiquantum nuclear resonances at optical orientation conditions. In 1976 Boris and David Mirlin were the first to observe the luminescence of hot electrons in semiconductors and the effect of momentum alignment of photoelectrons by linearly polarized light. The monograph Optical Orientation (North Holland, 1984), which Boris edited with Felix Meier, became a well-used guide for many condensed matter physicists.
Boris became director of the solid-state physics division of the Ioffe Institute in 1989. That appointment came during a period of political and economical reforms in Russia, when science budgets were dramatically cut. Under such difficult conditions Boris contributed greatly to preserving the material basis and scientific potential of his division and to strengthening the institute’s international scientific relations. Boris also joined St. Petersburg Electrotechnical University in 1973 as a professor at the chair of optoelectronics and remained affiliated with the university throughout his career.
Boris’s work was recognized through numerous honors. In 1992 he was elected a member of the Russian Academy of Sciences. He received the State Lenin Prize of the USSR in 1966, the State Prize of the USSR in 1976, the P. N. Lebedev Grand Gold Medal of the Russian Academy of Sciences in 1996, and the A. G. Aronov International Intellectual Fund’s Prize in 1998. He was a member of several national and international commissions. He also was editor-in-chief of Physics of the Solid State (Fizika tverdogo tela) from 1988 until his death.
Boris had an unusually brilliant memory. He was well read in history and classic literature, especially Russian poetry; David Samoylov, an eminent poet, was his friend. Boris was fond of music and art, particularly Russian vanguard paintings, and was no less proud that he had been the first to “discover” notable painters Minas Avetisyan and Avtandil Varazi than he was of his own scientific discoveries. A number of his essays and reminiscences were published in literary magazines.
A superb storyteller, Boris was famous for his paradoxes and witticisms. Even his scientific lectures were expressive and full of lyrical digressions. His outward appearance was inimitable: tall, slightly stooping, always elegantly dressed—one could recognize him from a distance in the institute’s corridors. Throughout his illness his wife Ruslana was beside him. Even after being admitted to the hospital, he continued meeting regularly with colleagues. With his death, the Ioffe Institute has lost something of its luster.
Boris was a talented, modest, well-educated, cultured man. He took to heart the destiny of science in Russia and pleaded its cause in letters to the government and in numerous articles. As is fitting for such a brilliant scientist, one of the minor planets of the solar system was named “Boris Zakharchenya” in 1998.
