Physics

Faculty Details

Hemachander Subramanian Assistant Professor
Joined the Institute in 2018
hemachander.subramanian@phy.nitdgp.ac.in
Education

Ph.D. (Theoretical and computational condensed matter physics)
State University of New York at Buffalo
Thesis:  Interaction of magnetism with atomic lattice geometry and nanoscale geometric frus-
tration
Supervisor: Prof. Jong E. Han

 

M.Tech (Computational techniques)
University of Hyderabad, India
Thesis: A novel image binarization algorithm
Supervisor: Prof. Prasanta K. Panigrahi



M.Sc (Physics) 
Specialization: Condensed matter physics
Pondicherry University

Work Experiences

Staff Scientist at Moffitt Cancer Center for Dr. Robert A. Gatenby, Nov 2012-2018 
Project:  We analyze the physics behind autocatalytic reactions that probably led to the formation of simple early life.  The goal is to elucidate the evolutionary pressures that operated on self-replicating heteropolymers and utilize them to understand the structure and function of DNA. Broken symmetries, which underlie structure formation during early universe and explain fascinating observations such as superconductivity, also seem to explain multiple disparate fundamental observations about the structure and function of nucleotides in DNA.


Research Assistant for Dr. Jong E. Han, SUNY Buffalo, 2009 - 2012
Project:  A longstanding unexplained experimental observation in the dilute magnetic semiconductor Ga(Mn)As has been its uniaxial magnetic anisotropy. It is not expected from simple symmetry considerations, since the crystal is cubic. We built a model which showed that there is symmetry breaking near Mn impurities in the crystal, resulting in local Jahn-Teller distortions. With the inclusion of growth strain, these distortions explain the observed anisotropies and transitions between different magnetization directions as hole density is varied.


Teaching assistant in the department of physics, SUNY Buffalo, 2008 - 2009 
Handled lab and recitation sessions to help undergraduate students understand the concepts in Electricity and Magnetism introduced in the classroom.  This is done through demonstration of relevant experiments and personal guidance, and through problem-solving sessions.  


Research Assistant for Dr.  Jong E. Han, SUNY Buffalo, 2007 - 2008
Project:  We theoretically studied the interaction between two magnetic ions placed near the surface of a semi-infinite jellium using perturbation theory (up to fourth order).  We found RKKY oscillations in both charge and spin density and interference due to the presence of the semi-infinite surface.


Research Assistant for Dr.  Jong E. Han, SUNY Buffalo, 2004 - 2007
Project: We numerically explored the effect of macroscopic geometric frustration in a symmetric soft-hard magnetic system in the presence of exchange, dipole and Zeeman interactions. We performed micromagnetic simulations and showed that the sytem behaves qualitatively differently in different regimes parametrized by the magnitude of the external Zeeman field, and has multiple degenerate energy minima, associated with the underlying structural symmetry. A rotating Zeeman field facilitates transitions between these degenerate minima within a given regime. We propose that this system can be used as a ternary logic device.


Teaching assistant in the department of physics, SUNY Buffalo, 2003 - 2004
Handled lab and recitation sessions for Mechanics, and Electricity and Magnetism courses. The work included individual student contact through office hours, and proctoring and grading. 


Research  assistant  for  Dr. Prasanta K. Panigrahi,  Physical  Research  Laboratory, Ahmedabad, India, 2002 - 2003
Project:  Proposed a novel image binarization algorithm that brings out local details by dividing the image into subimages and introducing continuity constraints between contiguous subimages. Initiated performance analysis and comparison with other known techniques.


Research assistant for Dr. V. Ravikumar, National Chemical laboratory, Pune, India, 2002
Project: Developed a reactor analysis toolkit in Matlab for Pacol chemical reactor at Reliance Industries. It measures performance of the reactor over time and predicts future behavior using multi-dimensional scaling technique.  Wrote extensive MATLAB code and documentation for the toolkit.

Research Interest

My current interest lay broadly in identifying the physical principles that underlie biological organization.  My focus over the last few years has been on elucidating the evolutionary pressures on primordial self-replicating systems and utilizing them to understand the physical and functional organization of the modern genetic material, DNA. I and my collaborators explain multiple fundamental properties of DNA through such an approach,  as demonstrated in our publications.


Understanding the implications of the presence or absence of structural and functional symmetries has been central to both the above and my other past projects. Identi?cation of broken symmetries, which has been successful in helping us understand the abiotic, physical world, also seem to provide insights into the biotic world. I would like to pursue this symmetry-based analysis of biological phenomena further, and would actively look out for more avenues where such analyses might be fruitful.

I am currently involved in understanding the implications of the presence of asymmetric cooperativity (please refer to our papers for definition) on the structure and function of DNA and RNA. This investigation has spawned a number of research directions, which I intend to pursue, one-by-one, with my future students and collaborators. 

Students interested to pursue projects related to the above-mentioned area can approach me by dropping an email or calling me. I am looking for students who are eager and enthusiastic about research in theoretical biology. 

Teachings

Scholars/ Students

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Publication

Awards and Recognitions

Council of Scientific and Industrial Research Fellowship, University Grants Commission, India, 2001

Gold Medalist in Master of Technology, University of Hyderabad, 2002

Silvestro Scholarship, University at Buffalo, 2006, 2008 and 2011

Ranked within top 93.2 percentile in the Graduate Aptitude Test in Engineering (Physics)

Topped entrance examinations for M. Phil and M. Tech degrees at University of Hyderabad

Stood first and second in qualifying examinations I and II resp. at University at Buffalo

Offered doctoral fellowship for theoretical physics at the prestigious Indian Institute of Sciences, Bangalore