Chanchal Kumar Majumdar, a leading condensed matter theorist in India, died on 20 June 2000 in Calcutta following a heart attack.
Majumdar was born on 11 August 1938 in Calcutta. He grew up during the last years of British rule in the highly nationalistic environment of Calcutta, where science was viewed as the great equalizing pursuit. Inspired by physicists Jagdeesh Chandra Bose, C. Venkata Raman, Satyendra Nath Bose, and Megh Nath Saha, all of whom worked in Calcutta at some point during the first half of the 20th century, many people were attracted to physics. In this environment, Majumdar was an extraordinary student; his record scores in state- and university-level examinations are an academic legend.
Majumdar completed his PhD in theoretical condensed matter physics with Walter Kohn in 1965 at the University of California, San Diego. His thesis was on the effect of interactions on positron annihilation in solids. That same year, he made a significant contribution: the Kohn–Majumdar theorem he formulated in collaboration with Kohn. The theorem proposes the continuity between bound and unbound states of a potential in a many-body continuum, a crucial clue to the orthogonality catastrophe that underlies the physics of the Kondo and Anderson impurity models. In 1966, Majumdar went to the Carnegie Institute of Technology in Pittsburgh for a postdoctoral fellowship. There, stimulated by the presence of James S. Langer and Robert B. Griffiths, he worked on problems in statistical mechanics and exactly solvable models such as the Ising model.
That same year, Majumdar joined the Tata Institute of Fundamental Research (TIFR) in Bombay, India, where he was instrumental in the early growth of condensed matter activity in a largely particle physics environment. He worked on problems ranging from the electronic (band) structure of cerium to exactly solvable spin models. He inculcated the culture of using the optimum mix of numerical and analytical methods to gain insight and obtain hard results. He interacted closely with experimental groups at TIFR on rare-earth magnetism, nuclear spectroscopy, and low-temperature physics. At TIFR, he computed exact eigenfunctions for finite chains and clusters, explored multimagnon bound states, and obtained energy-level spectra numerically. Perhaps the most significant outcome was the Majumdar-Ghosh model he developed with his student Dipan Ghosh in 1969. This model, with additional second neighbor interactions, is exactly solvable for a certain ratio of the coupling constants. It exhibits spontaneous breaking of discrete symmetry, namely lattice translations, and has a gap in its excitation spectrum. Fittingly, recent advances in synthetic materials science have seen real systems (such as copper germanate) that come close to fulfilling the conditions of solvability.
From 1969 to 1970, Majumdar spent a year on leave with Samuel F. Edwards at the University of Manchester in England. There, he wrote a prescient paper on the origin of non-Debye stress relaxation in glassy systems.
With his strong sense of history and commitment, Majumdar returned home to Calcutta in 1975 when he was offered the Palit Professorship at Calcutta University. He was a great teacher, enabling and inspiring a generation of physics graduates, some of whom are now among India’s leading physicists. As an example of his intellectual range, he worked with experimental physicists on irradiation effects in high-T c superconductors, with geologists on the determination of Fe2+/Fe3+ ratio in iron minerals from the region and its geological implications, and with engineers of the Haldia Dock Complex (Calcutta Port Trust) on modeling the seasonal and diurnal variations of large vessel navigability up the Hooghly River. In 1976, Majumdar was elected to the Indian Academy of Sciences.
In the last decade of his professional life, Majumdar was involved in creating and fostering the S. N. Bose Centre for Basic Sciences in Calcutta, from its beginnings as an idea to buildings, facilities, people, and an ethos. The center bears the mark of his perfectionism and phenomenal attention to detail, and is emerging as a major resource for physics.
Majumdar was deeply interested in present-day issues and in the history and culture of eastern India. He knew exactly where James Prinsep (who, in the 1830s, deciphered the script written on rocks—edicts Emperor Asoka wrote around 250 BC) lived in the Calcutta area; why a piece of a riverbank was named after him; and the lineage of the great Navya Nyaya logicians from Nadiya in Bengal (starting from the 13th century). His vigor, intellect, broad and deep interests, and infectious enthusiasm attracted many friends, students, and colleagues. They will remember his informality, openness, breadth of interest in physics, and, above all, his great integrity in relationships.
