Statistical and Quantum Physics · Soft Matter · Biological Physics
Somendra Mohan Bhattacharjee
Professor of Physics, Ashoka University
Professor of Physics, Ashoka University
Professor of Physics, Ashoka University. Sonipat-131029, India.
Previously: Senior Professor, Institute of Physics, Bhubaneswar.
Research interests include Statistical physics, Soft matter, DNA biophysics, Quantum phase transitions, and non-equilibrium systems.
Entry into Presidency College followed the usual rigid school life, though one punctuated by family tragedies.
A blind teenage love for equations, identities, and Euclid naturally led to physics. This was the early seventies.
The thwarted student rebellionThe mood of this period is captured in Kalbela, Samaresh Majumdar's celebrated Bengali novel, and was echoed by singer Kabir Suman in the 1990s in a song about a generation that lost lives trying to bring change., the emotional upheaval of Bangladesh, with millions on the roadThe Bangladesh refugee crisis inspired Joan Baez's 1972 "Song of Bangladesh", and, years later, Moushumi Bhowmik's haunting rendition of "Jessore Road", based on Allen Ginsberg's poem, revisiting the same tragedy. to Calcutta, Vietnam still further east, and Indira Gandhi's landslide victory.
… and then the declaration of the Emergency.
At that time, at that age, equations did not always balance.
The Physics Honours course was intended to last three years. Administrative delays contrived to stretch it to five — a fact that never quite found its way into official memory.
Physics remained a delight, made richer by unexpected time for classic films, Bengali theatre ("theaters"), and slow sips of the Feynman Lectures. Still, when exactly was graduation? Which year belongs on the record — 1975 or 1977?
The two-year M.Sc. course took two years, although the starting point had shifted. Inspirational classes at Science College, Rajabazar, and at Presidency only reinforced an already growing fascination with physics. The first bite of biology.
… and that sleepless night, everyone glued to the radio. … the announcement at dawn: Indira Gandhi defeated in the first post-Emergency election.
After a few months of undergraduate teaching at MMC College, Shyambazar, Calcutta, a new phase started: the Ph.D. years at Carnegie Mellon University (1980–1984).
A different country brought its own bewilderments—overstuffed supermarkets, highways, telephones that always worked, hesitant English, the first snowfall. Another novelty, the first encounter with a box called television — endlessly burping about El Salvador, Nicaragua, and eventually the absurd invasion of Grenada.
Unexpectedly, got enough independence in research. Earned my Ph.D. in good time; my wife, Sarama, earned hers too, from UPitt. The birth of our daughter, Saberi, added to that happiness.
The postdoctoral years. Polymers. The village-like quiet of Amherst, Massachusetts, followed by ritimoton3Ritimoton (Bengali): roughly "in the proper way" or "fully settled" — used here with affectionate irony for a settled suburban life. suburbia in the shadow of Bell Labs at Murray Hill. Our family welcomed a new member—our son, Paraj.
Another change of gear in 1988: joining the Institute of Physics, Bhubaneswar, as a faculty member — the beginning of a long education in what it means to do science in India.
When social wasps build nests collectively, without blueprints or central control, the result is not a perfect honeycomb but a subtler form of organization. The nests show remarkable local order alongside paired topological defects, similar to those seen in crystalline and two-dimensional materials. However, there are no indications of global translational order. The defects can migrate through transient rearrangements of the cells, revealing how collective biological construction generates order and defect-mediated dynamics without any central coordination.
Collaborators: Shivani Krishna (Biology)
Apoorva Gopinath, Tarini Hari
Order without a blueprint: hints of hexatic order?
A quantum system need not be heated or cooled to undergo a phase transition. Following a sudden quench, its own unitary time evolution can produce sharp dynamical transitions — dynamical quantum phase transitions (DQPTs).
Our work reveals a fascinating mathematical structure underlying these transitions, especially the emergence of fractal Julia sets. It also shows how boundary conditions can profoundly modify, or even suppress, a bulk dynamical transition.
Collaborators: Amina Khatun, Manmeet Kaur
Time itself can organize quantum phases.
How does a DNA molecule open? Force-induced unzipping offers a remarkable setting in which ideas from statistical physics, phase transitions, scaling, and dynamics meet molecular biology.
Our work established DNA unzipping as a genuine phase transition, developing its statistical-mechanical description in terms of Y-forks–the same junction that drives replication in biology–along with bubbles, critical scaling, and dynamics. More recent work has shown that circular DNA can melt predominantly through the growth of a single large bubble, revealing the important role of topology in DNA denaturation.
Even when no two strands are bound to each other, three strands of DNA can still form a bound state near melting. This is reminiscent of the Efimov problem in three-body quantum physics. It isn't a Borromean knot, though. Real topological knots do appear along the DNA chain, and that opens the door to studying how knots move along polymeric chains.
Collaborator: Garima Mishra, Souradeep Sengupta
Y-fork dynamics, knot dynamics: DNA's take on nonequilibrium statistical mechanics.
A digital archive of Bangla and Oriya literature, built and maintained alongside the academic pages. This grew out of one of the earliest search engines in any Indian language: an online, searchable Gitobitan first released on 21 February 2002. It was preceded by "Seicor," a script that preprocessed LaTeX Bengali (BangTeX) to place e-kar and i-kar signs correctly — an algorithm later extended to Oriya as well.
Ashoka University, Sonepat 131029, Haryana, India
Telephone: +91 130 2300799 (Off)
Email: somendra.bhattacharjee@ashoka.edu.in
Alternate: somen00@yahoo.com