The international condensed matter community tragically lost a leading member on 10 November 2003, when Ija Pavlovna Ipatova was struck down by a car while crossing the street near her home in St. Petersburg, Russia.
Ija was born in Smolensk, in the Soviet Union, on 19 December 1929. Her family moved to Leningrad one year later. During World War II, she was evacuated to Kislovodsk and to Tashkent. In 1945, she returned to Leningrad, the city she would call home for the rest of her life. She entered the physics department of Leningrad University in 1946 and graduated with honors five years later. She remained at the university as a graduate student in the department of theoretical physics. In 1955, she received the degree of candidate (PhD) in physics and, in May of that year, joined the A. F. Ioffe Physico–Technical Institute of the Academy of Sciences of the USSR as a junior research staff member. On earning her doctorate in 1969, she became a senior, then a leading (1985), and finally a principal (1991) research staff member.
Ija was a productive condensed matter theorist with a wide range of interests. She made significant contributions to the theory of Fermi liquids, an-harmonic vibrational properties of crystals, the effects of defects and disorder on the vibrations of crystals, the theory of space groups for phonons in superlattices, the group theory of second-order phase transitions at solid surfaces, and the surface-enhanced Raman effect. Particularly notable was her work, beginning in the early 1980s, on the scattering of light from electronic excitations in semiconductors—an effort that made it possible to obtain kinetic coefficients such as mobilities and thermal conductivities of those materials by purely optical (scattering) measurements. In the course of that research, she worked closely with experimentalists, namely, Bahish Bairamov at the Ioffe Institute and Manuel Cardona at the Max Planck Institute for Solid-State Research in Stuttgart, Germany; both scientists stimulated her research and confirmed its theoretical predictions.
Other significant contributions included her work on the instability of ternary and quaternary semiconductor compounds that are the basis of present-day semiconductor opto- and microelectronics, and the structures to which that instability gives rise. Anew mechanism for the spontaneous formation of semiconductor superlattices, an idea generated by Ija and her students, was used by the Ioffe Institute to create a new type of laser diode.
A theorist who worked well with experimentalists, Ija also successfully interacted with international groups. Following the publication of her contribution to the second edition of Theory of Lattice Dynamics in the Harmonic Approximation (Academic Press, 1971), written by one of us (Maradudin) and others, she became the human embodiment of Russian condensed matter physics for many Western physicists. Her international colleagues missed her during the 1970s and early 1980s, when she was not allowed to travel to the West. As soon as she could, though, she resumed her interactions and visits to institutions around the world.
In addition to her research, Ija was committed to pedagogy. In 1973, she received a joint appointment, initially as associate professor, and then, in 1976, as professor, in the department of semiconductor physics and nano-electronics at the Leningrad Polytechnic Institute (now the St. Petersburg State Polytechnical University). In those capacities, she changed the traditional approach to teaching classical physics by creating a new and original course of lectures, which led to the publication of a two-volume General Physics by the university in 2003 and Introduction to Solid-State Electronics, written with Vladimir Mitin, published in the US (Addison-Wesley) in 1996 and in Russia (Technical U. Press Center) in 1999. Ija received many awards for her teaching. However, not all of her teaching took place in the classroom. She gathered around her a group of graduate students and young collaborators actively working the area of the theory of semiconductors, and trained them very well.
Ija helped organize many Russian and international conferences and schools. She also chaired several scientific councils of the Academy of Sciences and served as a member of numerous scientific commissions and boards.
As a woman working in a field dominated by men, Ija was a great supporter of women scientists. She was one of the founders of the organization Women in Basic Science, which was established in 1999 within the Ioffe Institute.
Even during the most severe times in the Soviet Union, Ija maintained her integrity, clear-thinking manner, independence, and loyalty to universal human values in her relationships with colleagues. She was a truly decent human being—friend, colleague, teacher. Our memories of her will forever remain in our hearts and in the hearts of all who knew her.
