RESEARCH INTERESTS:
- Quantum Many Body Physics and Quantum Field Theoretical Studiesof Quantum Condensed Matter System.
- Cavity Quantum Electrodynamics.
- Non-equilibrium Statistical Physics.
- Quantum Phase Transition and Topological Quantum Phase Transition.
- Geometric Structure of Space-Time and Quantum Geometrical Tensor.
CURRENT ACADEMIC PROJECTS:
2nd DST PROJECT: Topological States of Superconducting Nanowires and interacting light-matter systems at nano scales.Principal Investigator: Sujit SarkarProject Students: Mr. Rahul Sharma (JRF Student), Mr. Ranjith Kumar R(JRF student).
Research Highlights:
- The Physics of different physical systems at nanoscale are interest ing in their own right. This research project has few scientific objectives for answering fundamental questions currently debated in the literature on the topological properties in superconducting nanowire and interacting lightmatter physics.
- The description of topological excitations like quantum phase slip center in disordered superconducting nanowire and the appearance of Berezinskii-Kosterlitz-Thouless transition in interacting light-matter physics areamong the most important problems of topological quantum phase transition.
- Find the relation between the topological invariant number and thephysical quantity of the system.
- The objective of this project is to find the answers of these questions and if possible the interrelations between them.
- Sarkar, S. Quantum phase diagram of granular superconducting quantum dots (2008) Nuclear Phyics B 795, pp 569 -578.
- Sarkar, S. Quantum Phase Diagram of a Spin-1/2 Antiferromagnetic Chain with Magnetic Impurities (2008), Nuclear Physics B 801, 346-354.
- Sarkar, S. Quantum phases in superconducting quantum dots array (2007), Phys. Rev. B 75,014528-014532.
- Sarkar, S. Quantum phase diagram of superconducting quantum dots array (2006), Euro Phys Lett 76, 1172-1177.
- Sarkar, S. Critical and off-critical properties of an anisotropic (XYZ) spin 1/2 chain under a transverse magnetic field (2006), Phys. Rev. B 74 052410-74052418.
- Sarkar, S. Physics of Majorana modes in interacting helical liquid (2016), Nature Sci.Rep. 6, 30569 doi:10.1038/srep30569.
- Sarkar, S. Topological Quantum Phase Transition and Local Topological Order of Light in a One Dimensional Array of Nonlinear Cavities (2017), Nature Sci. Rep. 7, 4159 doi:10.1038/srep41598.
- Sarkar, S. Quantization of geometric phase with integer and fractional topological characterization in a quantum Ising chain with long-range interaction (2018)NatureSci Rep DOI:10.1038/s41598-018-24136-1.
- Sarkar, S. A Study of Interaction Effects and Quantum Berezinskii- Kosterlitz-Thouless Transition in the Kitaev Chain (2018) Nature Sci Rep https://doi.org/10.1038/s41598-020-57796-z
Scientific Collaboration:
- Prof. C. D. Hu (The National Taiwan University).
- Prof. Masaki Tesuzaka (Tokyo, Japan).
- Prof. Igor Goryni (Karlshrue, Germany).
- Prof. M. Kumar (S. N. Bose Centre).
- Prof. Prosenjit Singhadeo (S. N. Bose Centre).
- Dept of Science and Technology (DST) project on “Geometric phase of quantum phase transition in quantum many-body systems” (2 JRF positions, Rs. 27 lakhs).
- Indo-Taiwan project on Quantum spin systems and transport (co-guiding two PhD students in Taiwan)
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Associate Professor, PPISR: Jan 2018--present
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Assistant Professor, PPISR: 2007 -- 2017
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Faculty Fellow, PPISR: 2005 -- 2007
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IISc Physics Department (year 1997-1998)
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Bar-Ilan University, Physics Department (year 1999-2000)
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Max-Planck Institute, Germany as a Guest Scientist (year 2000-2002)
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The Weizmann Institute of Science (year 2002-2005).
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Associateship position at S. N. Bose National Centre for Basic Sciences (since 2016 and continue)
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Visiting Scientist Positions: Tata Institute of Fundamental Research(Mumbai) National Centre for Theoretical Science (NCTS, Taiwan), Karl-shrue Institute of Technology, Germany
RECOGNITIONS/ACHIEVEMENTS:
- International Meeting on Many Body Localization at ICTS, November’2019.
- International Meeting on Quantum Phases for Quantum Matters, December’2019.
- Seminar given in ICTS on ”Emergent of Parity-Time Symmetry at Quantum Criticality” on 21st February 2020, in Indian Statistical Physics Community Meeting.
- International Conference on “Non-comutative Geometry and Quantum State”at S. N. Bose Centre, Kolkata , November’2018.
- Seminar given in International Centre of Theoretical Science on ”Conformal-Field Theory Study for the Topological State of Matter”, 15th February 2019, in Indian Statistical Physics Community Meeting.
- ”Bangalore Statistical Physics School” at the ICTS, June (2018).
- ”Workshop on Exactly Integrable System” at the ICTS, July (2018).
- “Discussions Meeting on Topology” at ICTS, June (2018).
Current PhD students
- Mr. Ranjith Kumar R (SRF Student)
Thesis Title: Topological Phase Transition at Quantum Criticality in One-Dimensional Topological Systems.
Thesis Summary: In this thesis work, we explore an intriguing interplay between topology and criticality in a generic model representing the topological insulators and superconductors. An unusual multicritical phenomenon occurs because of the edge modes localization at quantum criticalities, which leads to a new class of topological phase transition between distinct critical phases. We explore the existence of such transition and develop various theoretical frameworks, which work at criticality, to characterize them. We discuss the bound state solution of the Dirac equation, winding number, correlation factors, scaling theory of the curvature function, critical exponents, scaling laws and entanglement entropy, etc to characterize the multicritical points that separate the critical phases. We also discuss the numerical evidence and experimental observabilities of this phenomenon.
Other Research Interests: Non-Hermitian topological systems, Renormalization group method for topological systems, Interacting topological systems etc.
Email: ranjith@poornaprajna.org; ranjith.btd6@gmail.com
Google Scholar: link
Orcid Id: https://orcid.org/0000-0002-5181-7374
2. Mr. Y. R. Kartik (SRF Student)
Thesis Title: Geometry, criticality and topological transitions in Hermitian and non-Hermitian systems.
Thesis Summary: In condensed matter physics, study of geometry plays an important role in characterizing different quantum phases and also the criticality. Especially, the study becomes more relevant in systems which lack order parameter such as topological state of matter. These phenomenons are deeply rooted with the electronic band structure itself. The recent advances advances in the area of quantum devices, quantum sensors and quantum computation stresses the necessity of geometry and criticality in condensed matter systems. This thesis comprises the study of criticality and geometry of topological long-range models in the Hermitian and non-Hermitian framework covering the topics at zero and finite temperature.
Other Research Interests: Quantum many-body physics, light-matter interaction, non-Hermitian topological state of matter, finite temperature analysis, out-of-equilibrium systems.
Email: kartik@poornaprajna.org, yrkartik@gmail.com
Google Scholar: link
Orcid Id: https://orcid.org/0000-0002-0469-9213