I joined Shiv Nadar University, Delhi-NCR in December 2014, from the RIKEN Wako Institute, Japan, where I started after receiving the prestigious Foreign Postdoctoral Researcher (FPR) Fellowship of RIKEN. Prior to that, I was a Post-doctoral Research Fellow (with part-time appointment as Postdoctoral Teaching Fellow) in the renowned group of Prof. G. A. Sawatzky at the University of British Columbia, Vancouver, Canada, with a brief stint as a Visiting Research Associate in the Department of Condensed Matter Physics & Material Science, S.N. Bose National Centre for Basic Sciences, Kolkata, in between.
I did my M.S. and Ph.D. in the Department of Physics, Indian Institute of Science, Bangalore, under the Integrated Ph.D. program. I am a Theoretical Condensed Matter Physicist, specializing in the field of Strongly Correlated Electron Systems, where electron-electron interactions cannot be treated as a perturbation to its motion in the crystal potential, resulting in the breakdown of conventional band-structure description for such systems, at least in the rigourous sense. On one hand, this field helps us to better understand the exotic phenomena that can emerge out of strong, non-perturbative interactions between electrons in a narrow-band solid, like compounds of transition metals, rare-earths and actinides. On the other hand, a basic understanding of the physics of these materials helps to design “smart materials” with advanced and energy-efficient functionalities.
I have been working in this field for more than a decade, trying to model the ground state (low-energy) as well as the spectroscopic (high-energy) properties of correlated electron systems, under the mentorship of and in collaboration with leading international experts in the field. More specifically, my research interests lie in the Modeling of Electronic and Magnetic properties of Strongly Correlated Systems, X-ray Spectroscopies, Spin & Orbital Magnetism and Magneto-crystalline Anisotropy in Nano-structured materials, and development of New Computational Tools for Correlated Systems. Our work has been published in leading International Journals and is well-cited.
The research in our group can be broadly classified as Theoretical Condensed Matter Physics. More specifically, our research focuses on the field of Strongly Correlated Electron Systems (Ground State as well as Spectroscopic properties)., where electron-electron interactions cannot be treated as a perturbation to its motion in the crystal potential, resulting in the breakdown of conventional band-structure description for such systems, at least in the rigourous sense.
On one hand, this field helps us to better understand emergent phenomena that can arise out of strong, non-perturbative interactions between electrons in narrow-band solids, like compounds of transition metals, rare-earths and actinides. The hallmark of this is seen in exotic phenomena like colossal magnetoresistance in the Manganites, high-temperature superconductivity in the Cuprates, spin-charge separation and charge fractionalization in low-dimensional correlated systems, and the Kondo effect, to name a few. In such phenomena one simply cannot think of each electron independently, but must take into account the collective behaviour of a macroscopically large number (~ Avogadro's Number) of electrons, all acting in unison. On the other hand, a basic understanding of the physics of these materials helps in designing “smart materials” with advanced and energy-efficient functionalities.
Since treating the full correlation problem for an infinite solid is an unsolvable problem, the challenge for theory is to continuously develop newer and more efficient analytical approximations and numerical techniques to better understand the properties of these “quantum materials”, as constantly emerging from experiments. We have been working in this field for more than a decade, trying to model the ground state (low-energy) as well as the spectroscopic (high-energy) properties of correlated electron systems, in collaboration with leading experts in the field, both in India and abroad. We are interested both in model problems as well as in complex real materials. Our research interests and efforts are traditionally directed towards the following broad areas :
- Electronic and magnetic properties of strongly correlated electron systems : Including mixed-valent systems, systems with strong spin-orbit coupling (e.g., 4d and 5d transition metal oxides), systems exhibiting exotic spin-orbital and hidden order.
- Modeling of high-energy X-ray spectroscopies : e.g. XAS, AES, XPS, NIXS, RIXS etc. in strongly correlated systems.
- Spin/orbital magnetism and magneto-crystalline anisotropy in nano-structured materials : e.g., surfaces/thin-films/multilayers/nano-particles etc.
- Development of new computational tools for correlated electron systems.
More recently, I have developed an interest in some newer reaearch areas and am already pursuing active research in some of them. These are listed below :
- Calculation of High-energy Optical Conductivity in Strongly Correlated Electron Systems (related to my DST Project ECR/2016/002054).
- Application of Random Matrix Theory (RMT) to Disordered Quantum Electronic and Spin Systems.
- Investigation of Astrophysical Magnetism using the methods of Statistical Physics.
- Topological Aspects in Condensed Matter Physics.
- Integrability, Ergodicity and Quantum Chaos in Quantum Lattice Models.
I love teaching and am open to teaching almost any Core course and designing new Electives. Since January 2015, I have taught the following courses at SNU :
- PHY102 : Introduction to Physics II, Laboratory (Under-graduate Core). [Spring 2015]
- PHY203 : Introduction to Mathematical Physics I (Under-graduate Core). [Monsoon 2017, 2018]
- PHY304 : Condensed Matter Physics (Under-graduate Core). [Spring 2015, 2016 & 2021]
- PHY305 : Quantum Mechanics I (Under-graduate Core). [Monsoon 2015-2020]
- PHY306 : Quantum Mechanics II (Under-graduate Core). [Spring 2016-2022]
- PHY417 : Topics in Quantum Many Body Theory (Under-graduate Advanced Elective, Suitable for Post-Graduates too). [Spring 2017-2018, Monsoon 2019-2021]
- PHY508 : Review of Quantum Mechanics (Post-graduate Core). [Monsoon 2015]
- CCC 422 : Demystifying the Strange Quantum World for the Layman [Spring 2020 (2 batches), Monsoon 2021 (one batch), Spring 2022 (two batches)]
- PHY301 : Classical Mechanics (Under-graduate Core). [Monsoon 2021]
DOCTORAL RESEARCH STUDENTS :
- Debojyoti Kundu
UNDERGRADUATE RESEARCH STUDENTS :
I. UNDERGRADUATE THESIS
2019-2020 [Graduated 2020]
- Kartikeya Rambhatla (Grade : A-).
2018-2019 [Graduated 2019]
- Vikas S. Bhat (Grade : A-, Pursuing Integrated Ph.D. at TIFR, Mumbai).
- Ninaad Adhvaryu (Grade : A-, About to start Masters in Physics at University of Stuttgart, Germany.)
2017-2018 [Graduated 2018]
- Siddharth Seetharaman (Grade : A, Pursuing Ph.D. at Ohio State University, USA).
- Girish Kumar (Grade : A-, Pursuing Masters in Astrophysics at University of Amsterdam, The Netherlands).
- Prakriti Kayastha (Grade : A-, Pursuing Ph.D. at TIFR, Hyderabad).
II. OPPORTUNITIES FOR UNDERGRADUATE RESEARCH (OUR)
- Akshat Pandey
Invited Speaker at the International Conference “5th Young Investigators Meet on Quantum Condensed Matter Theory (YIMQCMT-2021)" organized by NISER, Bhubaneshwar, during November, 2021.
Invited Speaker at the International Conference “Interdisciplinary Topics in Advanced Materials (ITAM-2021)” organized jointly by IISc and JNCASR, Bangalore during July, 2021
NORDITA Academic Visitor in the Astrophysics Group of Nordic Institute for Theoretical Physics (NORDITA), Stockholm, Sweden (June, 2019).
Early Career Research Award, SERB (DST), India.
Selected for the prestigious RIKEN Foreign Postdoctoral Researcher (FPR) Fellowship, RIKEN, Japan (about 20 candidates selected Internationally every year, including the fields of Physics, Chemistry, Biology, Medicine and Engineering)
Spontaneously offered a Post-doctoral Position in the renowned Sawatzky Group, at the University of British Columbia, Vancouver, Canada, after receiving a exceptionally good Ph.D. Thesis Report from Prof. G. A. Sawatzky, a father figure in the field.
Selected for the Integrated Ph.D. Fellowship/Program of the Indian Institute of Science, Bangalore, India. Followed by the IISc JRF and SRF Fellowships in 1999 and 2002.
National Merit Scholar (1997) (Govt. of India) on the basis of B.Sc. (Hons.) results.
National Merit Scholar (1994) (Govt. of India) on the basis of XII std. results (ranked 40th in the state).