Lev Landau

Lev Landau
Born	Lev Davidovich Landau 22 January 1908
Birthplace	Baku, Caucasus Viceroyalty, Russian Empire
Died	1 April 1968 Moscow, Soviet Union
Nationality	Soviet
Occupation	Theoretical physicist
Known for	Theory of superfluidity, Ginzburg–Landau theory, Landau damping, Fermi liquid theory, Course of Theoretical Physics
Education	D.Sc., Leningrad Physico-Technical Institute (1934)
Children	1
Awards	Nobel Prize in Physics (1962), Stalin Prize (1946), Max Planck Medal (1960)

Lev Davidovich Landau (Лев Дави́дович Ланда́у (Russian: Лев Дави́дович Ланда́у); 22 January 1908 – 1 April 1968) was a Soviet theoretical physicist whose work spanned nearly every branch of the discipline, from quantum mechanics and condensed matter physics to plasma physics and quantum electrodynamics. Born in Baku to a Jewish family, Landau displayed extraordinary mathematical talent from childhood and entered university at the age of fourteen. Over the course of a career that took him from the lecture halls of Leningrad to the research institutes of Kharkiv and Moscow, he produced foundational work on superfluidity, phase transitions, diamagnetism, Fermi liquids, and superconductivity, among numerous other subjects. His ten-volume Course of Theoretical Physics, co-authored with Evgeny Lifshitz, became one of the most influential and widely used textbook series in the history of physics. Landau received the Nobel Prize in Physics in 1962 for his mathematical theory of superfluidity, which explained the behavior of liquid helium II at temperatures below 2.17 K. He was considered one of the last physicists to possess a comprehensive command of all areas of theoretical physics, and his influence extended through generations of students whom he trained through a notoriously demanding set of examinations known as the "Landau minimum."

Early Life

Lev Davidovich Landau was born on 22 January 1908 in Baku, then part of the Caucasus Viceroyalty of the Russian Empire. His father, David Lvovich Landau, was an engineer who worked in the petroleum industry in the oil-rich region around Baku. His mother, Lyubov Veniaminovna Garkavi-Landau, was a physician who had studied medicine and also conducted research in physiology. The family was Jewish, and Landau grew up in a cultured, professionally accomplished household in a city that was then one of the major industrial centers of the Russian Empire.

Landau was recognized as a mathematical prodigy from an early age. He reportedly learned to differentiate at the age of twelve and to integrate by the age of thirteen. He attended the Baku Economical Technical School before enrolling at Baku State University at the remarkably young age of fourteen. His precocity in mathematics and physics set him apart from his peers, and he soon transferred to Leningrad State University to pursue more advanced studies in physics.

Growing up during a period of immense political upheaval — the Russian Revolution of 1917 and the subsequent civil war defined the years of his childhood — Landau's formative experiences were shaped both by the intellectual stimulation of his family environment and the turbulent conditions of early Soviet society. Despite these disruptions, his talent was evident enough to earn him early admission to university and rapid advancement through the Soviet academic system.

Education

Landau began his university studies at Baku State University in 1922, when he was just fourteen years old. He simultaneously enrolled in the faculties of physics-mathematics and chemistry before deciding to focus exclusively on physics. In 1924, he transferred to Leningrad State University, which offered a more rigorous physics program and access to leading researchers. He completed his diploma there in 1927, at the age of nineteen.

Following his graduation, Landau began postgraduate work at the Leningrad Physico-Technical Institute, where he came into contact with the country's most prominent physicists. Between 1929 and 1931, he traveled abroad on a Soviet government scholarship, an opportunity that proved transformative for his scientific development. During this period, he visited Germany, Switzerland, the Netherlands, England, and Denmark, meeting and collaborating with some of the leading figures in physics, including Max Born, Werner Heisenberg, Wolfgang Pauli, and, most significantly, Niels Bohr at his institute in Copenhagen. Landau himself later identified Bohr as his primary intellectual mentor and considered the time spent in Copenhagen as the most formative period of his scientific career. He completed his Doctor of Sciences degree at the Leningrad Physico-Technical Institute in 1934.

Career

Early Research and Kharkiv Period (1927–1937)

Even before completing his diploma, Landau had begun publishing significant work. At the age of nineteen, he published his first scientific paper, which included the introduction of the density matrix concept in quantum mechanics — a contribution made independently of and concurrently with John von Neumann, who arrived at the same formulation through a different approach. This early work demonstrated Landau's ability to address fundamental questions at the forefront of theoretical physics.

During his time abroad from 1929 to 1931, Landau produced several important papers. His quantum mechanical theory of diamagnetism, which described the behavior of electrons in a magnetic field and predicted the quantization of their orbital motion (now known as Landau levels), was published during this period and became a cornerstone of solid-state physics.

In 1932, Landau moved to Kharkiv (then the capital of the Ukrainian Soviet Socialist Republic), where he became the head of the Theoretical Physics Department at the Kharkov Physico-Technical Institute. He also held positions at Kharkov Polytechnic Institute and Kharkov University. During his Kharkiv years, Landau established a vigorous school of theoretical physics and developed his famous comprehensive examination system, known as the "theoretical minimum" or "Landau minimum," which prospective students were required to pass before being accepted to work under him. The examination covered the entirety of theoretical physics and was notoriously difficult; over the decades, only about forty students succeeded in passing it.

At Kharkiv, Landau also began his collaboration with Evgeny Lifshitz, who had been one of his students and who would become his most important long-term scientific partner. Together they embarked on writing the Course of Theoretical Physics, a monumental series of textbooks that would eventually comprise ten volumes covering classical mechanics, classical field theory, quantum mechanics, statistical physics, fluid mechanics, electrodynamics, elasticity theory, and other areas. The series, often referred to simply as "Landau and Lifshitz," became standard reference texts for generations of physicists worldwide and is still widely used in physics departments.

Landau's Kharkiv period also saw his development of the theory of second-order phase transitions in 1937, a work of enormous significance for condensed matter physics. In this theory, he introduced the concept of the order parameter, a mathematical device that became one of the most widely used tools in theoretical physics for describing transitions between different states of matter.

Move to Moscow and the Institute for Physical Problems (1937–1962)

In 1937, Landau moved to Moscow at the invitation of Pyotr Kapitsa, who had recently established the Institute for Physical Problems. Landau became the head of the theoretical division at the institute, a position he would hold for the remainder of his active career.

Shortly after arriving in Moscow, in 1938, Landau was arrested by the Soviet secret police (NKVD) on charges of espionage and anti-Soviet activities. He was held in prison for one year before being released in 1939, reportedly following a personal intervention by Kapitsa, who wrote a letter to Joseph Stalin vouching for Landau's importance to Soviet science. The arrest took place during the Great Purge, a period in which many Soviet intellectuals and scientists were imprisoned or executed. The experience had a lasting effect on Landau, though he continued his scientific work with undiminished intensity after his release.

It was at the Institute for Physical Problems that Landau produced what is often considered his most celebrated work: the theory of superfluidity. In 1941, he published his mathematical explanation of the properties of liquid helium II — the superfluid phase of helium-4 that exists at temperatures below approximately 2.17 K (the lambda point). Kapitsa had experimentally discovered superfluidity in 1938, and Landau's theoretical framework provided the explanation by introducing the concept of two types of elementary excitations in the liquid: phonons (quantized sound waves) and rotons (a type of excitation unique to the superfluid). This two-fluid model successfully accounted for the remarkable properties of superfluid helium, including its ability to flow without viscosity. It was for this work that Landau would later receive the Nobel Prize in Physics.

Throughout the 1940s and 1950s, Landau continued to produce groundbreaking work across multiple areas of physics. In 1950, together with Vitaly Ginzburg, he developed the Ginzburg–Landau theory of superconductivity, a phenomenological model that described the transition from normal to superconducting states using the order parameter concept from his earlier phase transition theory. The Ginzburg–Landau theory proved enormously influential and provided the framework upon which the later microscopic BCS theory of superconductivity was built.

Landau also made fundamental contributions to the theory of Fermi liquids, providing a theoretical framework for understanding the behavior of interacting fermions in metals and in liquid helium-3. His Fermi liquid theory became a cornerstone of condensed matter physics. In plasma physics, he predicted the phenomenon now known as Landau damping — the damping of collective oscillations in a plasma without collisions between particles — which was later confirmed experimentally and became fundamental to the understanding of plasma behavior.

In quantum electrodynamics, Landau and his collaborators identified what became known as the Landau pole (or Moscow zero), a singularity in the running of the coupling constant that raised deep questions about the internal consistency of quantum electrodynamics at high energies. He also contributed the two-component theory of neutrinos and developed Landau's equations for S-matrix singularities, both important results in particle physics.

During the late 1940s and 1950s, Landau was involved in the Soviet nuclear weapons program, contributing theoretical calculations. He received the Stalin Prize in 1946, partly in recognition of contributions during this period.

Teaching and the Landau School

Landau's influence as a teacher and mentor was as significant as his research contributions. In addition to his positions at Kharkov University and the Institute for Physical Problems, he held a position at the Moscow State University Faculty of Physics. His "theoretical minimum" examination system became legendary in the physics community. The exam covered all major areas of theoretical physics, and Landau personally administered it. Among those who successfully passed the theoretical minimum and went on to distinguished careers were Evgeny Lifshitz, Isaak Khalatnikov, Lev Gor'kov, Lev Pitaevskii, Igor Dzyaloshinskii, and Aleksandr Akhiezer.

Landau was known for his sharp, sometimes cutting wit and his exacting standards. He reportedly ranked physicists on a logarithmic scale of achievement, placing Albert Einstein alone in the highest category (0.5), and figures such as Niels Bohr, Werner Heisenberg, Paul Dirac, and Erwin Schrödinger in the first class (1). He placed himself in the second-and-a-half class (2.5), later upgrading himself to 2 after his work on superfluidity. While this ranking system was informal and often recounted with humor, it reflected Landau's clear-eyed assessment of scientific achievement and his deep reverence for the founders of modern physics.

His personality was described in starkly different terms by different colleagues and contemporaries. He was characterized variously as "ruthless" and "gentle," "utterly repellent" and kind. A famous anecdote relates that he nailed a sign to his office door at Kharkov University that read "Beware, he bites!" — a characteristically provocative gesture that hinted at both his biting intellectual style and his sense of humor.

Personal Life

Landau married Kora Drobantseva, known as Concordia, and the couple had one son. He was of Jewish heritage, a fact noted by various biographical sources and one that placed him within a significant tradition of Jewish contributions to Soviet science, though Landau himself was not religiously observant.

On 7 January 1962, Landau was involved in a severe car accident on the road from Moscow to Dubna. His car collided with an oncoming truck, and he sustained critical injuries, including multiple fractures and severe head trauma. He was in a coma for several weeks, and his life was saved only through the efforts of an international medical team; physicists from around the world organized the shipment of rare medicines and equipment to Moscow to assist in his treatment. Although he eventually regained consciousness, Landau never recovered his full cognitive abilities and was unable to return to active scientific work. He lived for six more years in a diminished state, cared for by his family and colleagues.

Landau died on 1 April 1968 in Moscow, at the age of sixty, from complications related to the injuries sustained in the 1962 accident. He was buried at Novodevichy Cemetery in Moscow, one of the most prestigious burial sites in Russia, where many prominent figures of Russian science and culture are interred.

Recognition

Landau received numerous honors and awards throughout his career, reflecting the breadth and significance of his contributions to physics. His most prominent recognition was the 1962 Nobel Prize in Physics, awarded "for his pioneering theories for condensed matter, especially liquid helium." Due to his car accident earlier that year, Landau was unable to travel to Stockholm for the ceremony; the Nobel medal and diploma were instead presented to him in a Moscow hospital by the Swedish Ambassador to the Soviet Union.

Among his other major awards were the Stalin Prize (1946), the Max Planck Medal of the German Physical Society (1960), and the Fritz London Memorial Prize (1960), both of the latter recognizing his contributions to low-temperature physics and condensed matter theory. He also received two Lenin Prizes, the highest Soviet civilian award for scientific achievement, and was elected a full member of the Soviet Academy of Sciences.

Internationally, Landau was elected a Foreign Member of the Royal Society of London and a member of numerous other scientific academies, including the National Academy of Sciences of the United States, the Royal Danish Academy of Sciences, and the American Academy of Arts and Sciences.

On 22 January 2019, the 111th anniversary of Landau's birth, Google honored him with a Google Doodle, featuring imagery related to his work on superfluidity and condensed matter physics.

Legacy

Landau's legacy in theoretical physics is extensive. He is credited with laying much of the foundation of twentieth-century condensed matter physics, and his theoretical frameworks — the order parameter concept, the theory of phase transitions, the Fermi liquid theory, and the Ginzburg–Landau theory — remain central to the field. His work on superfluidity not only explained a fundamental quantum phenomenon but also opened new avenues of research that continue to be explored in contemporary physics, including in the study of ultracold atomic gases and quantum fluids.

The Course of Theoretical Physics by Landau and Lifshitz is considered one of the greatest achievements in physics pedagogy. The ten-volume series, known for its rigor, clarity, and comprehensive scope, has been translated into many languages and remains in print and in active use decades after its initial publication. It has shaped the education of theoretical physicists in the Soviet Union and worldwide, and its influence on physics curricula is difficult to overstate.

The Landau school of theoretical physics — the network of students, collaborators, and intellectual descendants trained through his theoretical minimum system — produced many of the leading Soviet and Russian physicists of the twentieth century. Among them, Vitaly Ginzburg went on to receive the Nobel Prize in Physics in 2003, and Alexei Abrikosov received the same prize in the same year, both for work rooted in the theoretical tradition Landau established.

Several physical concepts and phenomena bear Landau's name, including Landau levels, Landau damping, the Landau pole, and Landau quantization. The Landau Institute for Theoretical Physics, established in 1965 near Moscow, was named in his honor and became one of the world's leading centers for theoretical physics research.

Landau's ranking system for physicists, while informal, entered the lore of the physics community and continues to be discussed as a reflection of his uncompromising standards and his belief in a hierarchy of scientific achievement. His personality — brilliant, demanding, witty, and at times abrasive — made him one of the most memorable figures in the history of physics, as much for his human qualities as for his scientific contributions.