Vladimir Z. Kresin

Vladimir Kresin died on 28 July 2022 at age 88.

Vladimir’s lifelong calling was seeded by an inspiring high school teacher in postwar Moscow. Although he graduated with straight A’s and a “gold medal,” which entitled him to attend any university without entrance exams, Vladimir was denied entry into Moscow State University: The Soviet government’s infamous anti-Semitic pressure erected unspoken but omnipresent barriers to those labeled as ethnically Jewish. A wasted year later, in a stroke of luck, he found out about the physics faculty at the much lesser-known Pedagogical University. By an irony characteristic of the system, courses there were taught by stellar scientists who, with a “Jewish” stamp in their documents, were similarly kept out of Moscow State. Here Vladimir obtained his undergraduate degree, followed by a PhD under the mentorship of the brilliant theorist Boris Geilikman; he earned a DSc in 1968.

During 1957–58 Vladimir passed Lev Landau’s Theoretical Physics Minimum. (He recalled visiting Landau’s apartment for the first screening in mathematical methods.) Meeting Landau and joining a community for whom the beauty, breadth, and rigor of theoretical physics reigned supreme were life-forming experiences for Vladimir. As is the hallmark of the Landau school, Vladimir’s work combined sharp physical insight, powerful analytical technique, clear reasoning, and close attention to experiment. His top-class calculational skills were complemented by a talent to describe even complicated physical phenomena in an understandable way.

In an era stimulated by the appearance of BCS theory and its field-theoretical formulation by Lev Gor’kov, Vladimir investigated transport and electromagnetic properties of superconductors, strong-coupling and non-phonon mechanisms, and pairing phenomena in thin films, semiconductors, semimetals, multiband systems, and complex molecules.

After the USSR started allowing a trickle of Jewish residents to leave the country in the 1970s, Vladimir and his family applied for an exit visa. After a long nail-biting and jobless wait, they were allowed to go, and in 1979 they resettled in California. Joining the Lawrence Berkeley Lab’s National Resource for Computation in Chemistry, which was directed by William Lester, allowed Vladimir to restart his scientific life. He remained at LBL for the rest of his career, becoming a staff scientist and principal investigator.

Superconducting tunneling and the Josephson effect were a rich source of inspiration for Vladimir. His contributions to proximity effect physics exemplify his far-reaching vision, as reflected in recent progress on hybrid heterostructures and junctions with low-dimensional barriers. Later, this expertise led him to such milestones as the explanation of the cuprates’ pseudogap state and the prediction of high-temperature, high-current networks of superconducting nanocluster particles with electronic shell structure.

Many other papers were devoted to strong-coupling superconductivity and its implications for organic superconductors, fullerides, borocarbides, intercalated layered metallochloronitrides, etc. A key achievement was Vladimir’s 1987 Physics Letters A publication of an analytical expression for T_c, derived directly from microscopic theory, that is fully valid for any electron–phonon coupling strength.

An important share of Vladimir’s activity was concerned with a broad range of the physical properties of high-T_c cuprates. He demonstrated that strong electron–phonon coupling provided a unified and consistent description of these materials. He also showed that layered systems support acoustic plasmons and that interaction via such plasmons can further enhance superconducting pairing. Vladimir’s deep understanding of electron–phonon coupling as a giant nonadiabatic phenomenon was enriched by his work in molecular and chemical physics, where he contributed extensively to the theories of polyatomic photodissociation, nonadiabatic chemical dynamics, and catalysis.

Vladimir also made important contributions to the understanding of the unusual properties of doped manganites, the physics of thin films, structural transitions, relaxation cascades in solids, and other topics in condensed matter physics.

His last series of publications focused on the nearly room-temperature superconductivity found in hydride materials under high pressure and on strategies toward developing analogous ambient-pressure materials. These discoveries reaffirmed Vladimir’s conviction of the richness and promise of the science of superconductivity. The fact that pairing in these systems is enabled by strong electron–phonon coupling fell exactly in line with his ideas regarding the mechanisms of high T_c.

Vladimir co-organized many international meetings and co-edited their proceedings. He was proud of the 1987 Conference on Novel Mechanisms of Superconductivity, which became the first major meeting and proceedings volume following the discovery of high T_c.

Vladimir published many influential reviews and books; the last edition of the authoritative Superconducting State: Mechanisms and Materials (with S. Ovchinnikov and S. Wolf) appeared in 2021. His 1968 book, Superconductivity and Superfluidity, aimed to describe macroscopic quantum phenomena at the entry level and was the first such book on the subject published in the USSR. The second edition appeared in 1978, and an English-language version, updated jointly with Wolf, came out in 1990 as Fundamentals of Superconductivity.

For three decades Vladimir served as the editor of the Journal of Superconductivity and Novel Magnetism, working tirelessly to keep it at the forefront of the field and initiating many special-topic and Festschrift issues.

In addition to his supreme dedication to physics, Vladimir had an infectious love for music, opera, theater, art, and literature. He set high standards for science, art, honesty, and friendship, and he lived his life meeting these standards with passion, integrity, and humor.