Right after the creation of IRE its first director, Alexander Yakovlevich Usikov, started issuing job offers to theoretical physicists and mathematicians, graduates of the physics and mathematics departments of Karazin University. At that time in Kharkiv there were only three doctors of science majoring in theoretical physicists: A. I. Akhiezer, I. M. Lifshits and V. L. German. One of them, Veniamin Leontievich German, was asked by Alexander Yakovlevich to lead the department of theoretical physics.

At first glance, the idea of such a department might look not very understandable. The school of theoretical physics organized in our state by L. D. Landau at that time was focused mostly on fundamental problems, which were in general far from the problems of radiophysical science. Besides, the approach to the solution of a theoretical physicist and radiophysicist are quite different. Nevertheless, according to A. Ya. Usikov, the communication between the representatives of these two different “scientific cultures” must lead to the creation of new scientific directions.

And indeed, newly graduated representatives of the department of theoretical physics of the Karazin University (Kharkiv State University at that time) such as V. P. Shestopalov, E. A. Kaner, F. G. Bass, V. M. Kontorovich, etc, recruited to work at IRE, soon actively participated in the researched carried out at the Institute as well as suggested a number of new scientific directions.

It is important to point out the role of Prof. Emanuil Aizikovich Kaner in the department establishment. E. A. Kaner was one of the brightest representatives of the theoretical school of Ilya Mikhailovich Lifshits. The most important research of E. A. Kaner is related to the theory of plasma phenomena in metals. Thanks to the discovery of cyclotron resonance and other of his works in this field, there happened the reconsideration of the conventional idea about metals as a media in which the propagation of electromagnetic radiation is impossible. E. A. Kaner predicted the existence of different types of such oscillations which are able to penetrate inside the metal on a considerable depth, discovered new mechanism of their absorption (known as Landau magnetic attenuation), developed theoretical concept of single particle ballistic mechanism of the anomalous transparency of metals.

E. A. Kaner was one of the first scientists who started the research on magnetic acoustics of metals. He predicted acoustic cyclotron and helicon-phonon resonances, resonance in open orbits, giant quantum oscillations of the speed of sound, strong non-adiabatic effects in electron-phonon interaction, theoretical foundations of magnetic acoustoelectronics of metals on Rayleigh waves were developed.

He made an important contribution into the development of the instability and propagation problem of waves in semiconducting and gas-discharge plasma – E. A. Kaner predicted helical instability of coupled sound and spiral electromagnetic waves, developed theory of cyclotron parametric instability of a new type in semiconductors.

The fruitful scientific ideas of E. A. Kaner found their application in statistic theory of radiowaves propagation in turbulent troposphere and waves scattering on hydrometeors, in radiolocation, and other areas of modern radiophysics. During the last years of his life, E. A. Kaner actively studied magnetically doped waves in metals, some problems of magnetic breakdown, acoustic properties of low dimentional disordered systems, nonlinear electrodynamics of metals and semiconductors.

After the death of E. A. Kaner, since 1986 the theoretical physics department was led by one of the his talented disciples – Nikolay Mikhailovich Makarov, from 2001 till 2019 the department was led by another talented disciple of E. A. Kaner – Valeriy Aleksandrovich Yampol’skiy. Currently, the department is led by the disciple of V. A. Yampol’skiy – S. S. Apostolov.

More than two decades E. A. Kaner was teaching, being professor at Kharkiv State University. The cooperation between the theoretical physics department of IRE and Kharkiv National University are still being active. The department employees (V.A. Yampolsky, S.S. Apostolov, T.N. Rokhmanova) have teaching activities, supervise the diploma and master works. This ensures the succession of the department traditions. Before and now at the department works many talented young researchers.