Subhajit Sarkar

@srmist.edu.in

Assistant Professor, Engineering & Technology
Assistant Professor, Science & Humanities
S R M Institute of Science and Technology

Subhajit Sarkar


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https://researchid.co/subhajit.sarkar_uj

RESEARCH, TEACHING, or OTHER INTERESTS

Condensed Matter Physics, Statistical and Nonlinear Physics, Atomic and Molecular Physics, and Optics, Multidisciplinary
23

Scopus Publications

265

Scholar Citations

9

Scholar h-index

8

Scholar i10-index

Scopus Publications

  • The Spinterface Mechanism for the Chiral-Induced Spin Selectivity Effect: A Critical Perspective
    Subhajit Sarkar, Amos Sharoni, Oliver L. A. Monti, Yonatan Dubi
    ACS Nano, 2025
    The chirality-induced spin selectivity (CISS) effect, whereby chiral molecules preferentially transmit electrons of one spin orientation, remains one of the most intriguing and debated phenomena at the interface of spintronics, molecular electronics, and quantum materials. Despite extensive experimental observations across diverse platforms─including transport junctions, photoemission, and enantioselective chemistry─a comprehensive theoretical framework is still lacking. In this perspective, we critically examine the spinterface mechanism as a unifying explanation for the CISS effect. The spinterface model, which hypothesizes a feedback interaction between electron motion in chiral molecules and fluctuating surface magnetic moments, is shown to quantitatively reproduce experimental data across various systems and conditions. We contrast it with some existing theoretical models, highlighting key experimental features. Importantly, we also address open questions and criticisms of this model, including the nature of surface magnetism, the role of dissipation, and the applicability of the mechanism to nonhelical or electrode-free systems. By offering falsifiable predictions and reconciling theory with experimental raw data, this work aims to sharpen the dialogue surrounding the microscopic origin of CISS and stimulate further experimental and theoretical progress.
  • Approaching the scaling limit of transport through lattices with dephasing
    Subhajit Sarkar, Gabriela Wójtowicz, Bartłomiej Gardas, Marek M. Rams, Michael Zwolak
    Journal of Chemical Physics, 2025
    We examine the stationary-state equations for lattices with generalized Markovian dephasing and relaxation. When the Hamiltonian is quadratic, the single-particle correlation matrix has a closed system of equations even in the presence of these two processes. The resulting equations have a vectorized form related to, but distinct from, Lyapunov’s equation. We present an efficient solution that helps to achieve the scaling limit, e.g., of the current decay with lattice length. As an example, we study the super-diffusive-to-diffusive transition in a lattice with long-range hopping and dephasing. The approach enables calculations with up to 104 sites, representing an increase of 10 to 40 times over prior studies. This enables a more precise extraction of the diffusion exponent, enhances agreement with theoretical results, and supports the presence of a phase transition. There is a wide range of problems that have Markovian relaxation, noise, and driving. They include quantum networks for machine-learning-based classification and extended reservoir approaches for transport. The results here will be useful for these classes of problems.
  • Single cycle optical nonlinearity of transparent conducting oxides
    Ieng-Wai Un, Subhajit Sarkar, Yonatan Sivan
    Frontiers in Optics Fio 2025 in Proceedings Frontiers in Optics Laser Science 2025 Fio Ls Part of Frontiers in Optics Laser Science 2025, 2025
    We model the optical and electronic response of transparent conducting oxides to a single cycle intense pulse. This enables interpreting recent experimental observation of the strength of the nonlinear response, and its unexpected rapid relaxation.
  • Single cycle optical nonlinearity of transparent conducting oxides
    Ieng-Wai Un, Subhajit Sarkar, Yonatan Sivan
    Laser Science Proceedings Frontiers in Optics Laser Science 2025, 2025
    We model the optical and electronic response of transparent conducting oxides to a single cycle intense pulse. This enables interpreting recent experimental observation of the strength of the nonlinear response, and its unexpected rapid relaxation.
  • Time Crystals from Single-Molecule Magnet Arrays
    Subhajit Sarkar, Yonatan Dubi
    ACS Nano, 2024
    Time crystals, a unique nonequilibrium quantum phenomenon with promising applications in current quantum technologies, mark a significant advance in quantum mechanics. Although traditionally studied in atom-cavity and optical lattice systems, pursuing alternative nanoscale platforms for time crystals is crucial. Here we theoretically predict discrete time crystals in a periodically driven molecular magnet array, modeled by a spin-S Heisenberg Hamiltonian with significant quadratic anisotropy, taken with realistic and experimentally relevant physical parameters. Surprisingly, we find that the time crystal response frequency correlates with the energy levels of the individual magnets and is essentially independent of the exchange coupling. The latter is unexpectedly manifested through a pulse-like oscillation in the magnetization envelope, signaling a many-body response. These results show that molecular magnets can be a rich platform for studying time-crystalline behavior and possibly other out-of-equilibrium quantum many-body dynamics.
  • Impact of dephasing on nonequilibrium steady-state transport in fermionic chains with long-range hopping
    Subhajit Sarkar, Bijay Kumar Agarwalla, Devendra Singh Bhakuni
    Physical Review B, 2024
    Quantum transport in a non-equilibrium setting plays a fundamental role in understanding the properties of systems ranging from quantum devices to biological systems. Dephasing -- a key aspect of out-of-equilibrium systems -- arises from the interactions with the noisy environment and can profoundly modify transport features. Here, we investigate the impact of dephasing on the non-equilibrium steady-state transport properties of non-interacting fermions on a one-dimensional lattice with long-range hopping ($\\sim \\frac{1}{r^\\alpha}$). We show the emergence of distinct transport regimes as the long-range hopping parameter $\\alpha$ is tuned. In the short-range limit ($\\alpha \\gg 1$), transport is diffusive, while for the long-range limit ($\\alpha \\sim \\mathcal{O}(1)$), we observe a super-diffusive transport regime. Using the numerical simulation of the Lindblad master equation, and corroborated with the analysis of the current operator norm, we identify a critical long-range hopping parameter, $\\alpha_c \\approx 1.5$, below which super-diffusive transport becomes evident that quickly becomes independent of the dephasing strength. Interstingly, within the super-diffusive regime, we find a crossover from logarithmic to power-law system-size dependence in the non-equilibrium steady-state resistance when $\\alpha$ varies from $\\alpha \\leq 1$ to $\\alpha \\lesssim 1.5$. Our results, thus, elucidate the intricate balance between dephasing and unitary dynamics, revealing novel steady-state transport features.
  • Protecting coherence from the environment via Stark many-body localization in a Quantum-Dot Simulator
    Subhajit Sarkar, Berislav Buča
    Quantum, 2024
    Semiconductor platforms are emerging as a promising architecture for storing and processing quantum information, e.g., in quantum dot spin qubits. However, charge noise coming from interactions between the electrons is a major limiting factor, along with the scalability of many qubits, for a quantum computer. We show that a magnetic field gradient can be implemented in a semiconductor quantum dot array to induce a local quantum coherent dynamical ℓ−bit exhibiting the potential to be used as logical qubits. These dynamical ℓ−bits are responsible for the model being many-body localized. We show that these dynamical ℓ−bits and the corresponding many-body localization are protected from all noises, including phonons, for sufficiently long times if electron-phonon interaction is not non-local. We further show the implementation of thermalization-based self-correcting logical gates. This thermalization-based error correction goes beyond the standard paradigm of decoherence-free and noiseless subsystems. Our work thus opens a new venue for passive quantum error correction in semiconductor-based quantum computers.
  • The nonlinear optical response and electron dynamics in transparent conducting oxides
    Ieng Wai Un, Subhajit Sarkar, Yonatan Sivan
    2024 Conference on Lasers and Electro Optics CLEO 2024, 2024
    We describe a Boltzmann-based model for the electron dynamics and thermal and optical properties of transparent conducting oxides, and show that it explains experimental findings with no need for any ad-hoc changes used so far.
  • The nonlinear optical response and electron dynamics in transparent conducting oxides
    Ieng Wai Un, Subhajit Sarkar, Yonatan Sivan
    CLEO Fundamental Science CLEO Fs 2024 in Proceedings CLEO 2024 Part of Conference on Lasers and Electro Optics, 2024
    We describe a Boltzmann-based model for the electron dynamics and thermal and optical properties of transparent conducting oxides, and show that it explains experimental findings with no need for any ad-hoc changes used so far.
  • Temperature-dependence of the chirality-induced spin selectivity effect—Experiments and theory
    Seif Alwan, Subhajit Sarkar, Amos Sharoni, Yonatan Dubi
    Journal of Chemical Physics, 2023
    The temperature-dependence of the chirality-induced spin selectivity (CISS) effect can be used to discriminate between different theoretical proposals for the mechanism of the CISS effect. Here, we briefly review key experimental results and discuss the effect of temperature in different models for the CISS effect. We then focus on the recently suggested spinterface mechanism and describe the different possible effects temperature can have within this model. Finally, we analyze in detail recent experimental results presented in the work of Qian et al. [Nature 606, 902–908 (2022)] and demonstrate that, contrary to the original interpretation by the authors, these data actually indicate that the CISS effect increases with decreasing temperature. Finally, we show how the spinterface model can accurately reproduce these experimental results.
  • Electronic-Based Model of the Optical Nonlinearity of Low-Electron-Density Drude Materials
    Ieng-Wai Un, Subhajit Sarkar, Yonatan Sivan
    Physical Review Applied, 2023
  • Electronic and Thermal Response of Low-Electron-Density Drude Materials to Ultrafast Optical Illumination
    Subhajit Sarkar, Ieng Wai Un, Yonatan Sivan
    Physical Review Applied, 2023
  • Signatures of discrete time-crystallinity in transport through an open Fermionic chain
    Subhajit Sarkar, Yonatan Dubi
    Communications Physics, 2022
  • Emergence and Dynamical Stability of a Charge Time-Crystal in a Current-Carrying Quantum Dot Simulator
    Subhajit Sarkar, Yonatan Dubi
    Nano Letters, 2022
  • Theory of non-equilibrium 'hot' carriers in direct band-gap semiconductors under continuous illumination
    Subhajit Sarkar, Ieng-Wai Un, Yonatan Sivan, Yonatan Dubi
    New Journal of Physics, 2022
  • Hot" electron generation in plasmonic nanostructures - thermal vs. Non-thermal effects
    Optics Infobase Conference Papers, 2022
  • Defect production and quench dynamics in the three-dimensional Kitaev model
    Subhajit Sarkar, Dibyendu Rana, Saptarshi Mandal
    Physical Review B, 2020
  • Environment-Assisted and Environment-Hampered Efficiency at Maximum Power in a Molecular Photocell
    Subhajit Sarkar, Yonatan Dubi
    Journal of Physical Chemistry C, 2020
  • Fermi surface instabilities of symmetry-breaking and topological types on the surface of a three-dimensional topological insulator
    Subhajit Sarkar
    Physical Review B, 2018
  • Delocalization of charge and current in a chiral quasiparticle wave packet
    Subhajit Sarkar
    Physical Review B, 2018
  • Semi-phenomenological analysis of neutron scattering results for quasi-two dimensional quantum anti-ferromagnet
    Subhajit Sarkar, Ranjan Chaudhury, Samir K. Paul
    Journal of Magnetism and Magnetic Materials, 2017
  • Erratum: The connection between vortex-like topological excitations and conventional excitations in quantum ferromagnetic spin systems on two-dimensional lattice and their stability (International Journal of Modern Physics B (2015) 29:31 (22))
    Subhajit Sarkar, Ranjan Chaudhury, Samir K. Paul
    International Journal of Modern Physics B, 2015
  • The connection between vortex-like topological excitations and conventional excitations in quantum ferromagnetic spin systems on two-dimensional lattice and their stability
    Subhajit Sarkar, Ranjan Chaudhury, Samir K. Paul
    International Journal of Modern Physics B, 2015

RECENT SCHOLAR PUBLICATIONS

  • Quantum-optical theory of the few-femtosecond nonlinear optical response of Drude metals with a nonparabolic conduction band
    IW Un, S Sarkar, Y Sivan
    Physical Review B 113 (16), 165411 , 2026
    2026
    Citations: 1
  • Bipartite particle number fluctuations in dephased long-range lattice systems
    L Tater, S Sarkar, DS Bhakuni, BK Agarwalla
    Physical Review B 112, 205407 , 2025
    2025
    Citations: 6
  • Single cycle optical nonlinearity of transparent conducting oxides
    IW Un, S Sarkar, Y Sivan
    Laser Science, JW5A. 36 , 2025
    2025
  • The spinterface mechanism for the chiral-induced spin selectivity effect: A Critical Perspective
    S Sarkar, A Sharoni, OLA Monti, Y Dubi
    ACS nano 19 (43), 37484-37503 , 2025
    2025
    Citations: 6
  • Approaching the scaling limit of transport through lattices with dephasing
    S Sarkar, G Wójtowicz, B Gardas, MM Rams, M Zwolak
    The Journal of Chemical Physics 163 (11) , 2025
    2025
  • Time Crystals from single-molecule magnet arrays
    S Sarkar, Y Dubi
    ACS nano 18 (41), 27988–27996 , 2024
    2024
    Citations: 9
  • Protecting coherence from the environment via Stark many-body localization in a Quantum-Dot Simulator
    S Sarkar, B Buca
    Quantum 8, 1392 , 2024
    2024
    Citations: 8
  • The nonlinear optical response and electron dynamics in transparent conducting oxides
    IW Un, S Sarkar, Y Sivan
    2024 Conference on Lasers and Electro-Optics (CLEO), 1-2 , 2024
    2024
    Citations: 1
  • Impact of dephasing on non-equilibrium steady-state transport in fermionic chains with long-range hopping
    S Sarkar, BK Agarwalla, DS Bhakuni
    Physical Review B 109, 165408 , 2024
    2024
    Citations: 14
  • Ballistic vs. diffusive transport in metals
    Y Sivan, IW Un, S Sarkar
    arXiv preprint arXiv:2402.15226 , 2024
    2024
    Citations: 4
  • Impact of dephasing on nonequilibrium steady-state transport in fermionic chains with long-range hopping
    BK AGARWALLA, S Sarkar, DS Bhakuni
    American Physical Society , 2024
    2024
  • Temperature-dependence of the chirality-induced spin selectivity effect—Experiments and theory
    S Alwan, S Sarkar, A Sharoni, Y Dubi
    The Journal of chemical physics 159 (1) , 2023
    2023
    Citations: 34
  • Electronic-Based Model of the Optical Nonlinearity of Low-Electron-Density Drude Materials
    IW Un, S Sarkar, Y Sivan
    Physical Review Applied 19, 044043 , 2023
    2023
    Citations: 48
  • The nonlinear optical response and non-equilibrium electron dynamics in Indium-Tin-Oxide (ITO)
    S Sarkar, IW Un, Y Sivan
    Ultrafast Phenomena and Nanophotonics XXVII , 2023
    2023
  • Electronic and thermal response of low-electron-density drude materials to ultrafast optical illumination
    S Sarkar, IW Un, Y Sivan
    Physical Review Applied 19 (1), 014005 , 2023
    2023
    Citations: 28
  • “Hot” electron generation in plasmonic nanostructures–thermal vs. non-thermal effects
    Y Dubi, S Sarkar, IW Un, Y Sivan
    Novel Optical Materials and Applications, NoW5D. 3 , 2022
    2022
  • Signatures of discrete time-crystallinity in transport through open Fermionic chain
    S Sarkar, Y Dubi
    Communications Physics 5 (155) , 2022
    2022
    Citations: 36
  • Emergence and Dynamical Stability of a Charge Time-Crystal in a Current-Carrying Quantum Dot Simulator
    S Sarkar, Y Dubi
    Nano Letters 22 (11), 4445-4451 , 2022
    2022
    Citations: 21
  • Theory of non-equilibrium ``hot" carriers in direct band-gap semiconductors under continuous illumination
    S Sarkar, IW Un, Y Sivan, Y Dubi
    New Journal of Physics 24, 053008 , 2022
    2022
    Citations: 17
  • Theory of hot carriers and carrier heating in a semiconductor under continuous illumination
    S Sarkar, IW Un, Y Sivan, Y Dubi
    APS March Meeting Abstracts 40 (10), 1093-1102 , 2021
    2021

MOST CITED SCHOLAR PUBLICATIONS

  • Electronic-Based Model of the Optical Nonlinearity of Low-Electron-Density Drude Materials
    IW Un, S Sarkar, Y Sivan
    Physical Review Applied 19, 044043 , 2023
    2023
    Citations: 48
  • Signatures of discrete time-crystallinity in transport through open Fermionic chain
    S Sarkar, Y Dubi
    Communications Physics 5 (155) , 2022
    2022
    Citations: 36
  • Temperature-dependence of the chirality-induced spin selectivity effect—Experiments and theory
    S Alwan, S Sarkar, A Sharoni, Y Dubi
    The Journal of chemical physics 159 (1) , 2023
    2023
    Citations: 34
  • Electronic and thermal response of low-electron-density drude materials to ultrafast optical illumination
    S Sarkar, IW Un, Y Sivan
    Physical Review Applied 19 (1), 014005 , 2023
    2023
    Citations: 28
  • Emergence and Dynamical Stability of a Charge Time-Crystal in a Current-Carrying Quantum Dot Simulator
    S Sarkar, Y Dubi
    Nano Letters 22 (11), 4445-4451 , 2022
    2022
    Citations: 21
  • Theory of non-equilibrium ``hot" carriers in direct band-gap semiconductors under continuous illumination
    S Sarkar, IW Un, Y Sivan, Y Dubi
    New Journal of Physics 24, 053008 , 2022
    2022
    Citations: 17
  • Impact of dephasing on non-equilibrium steady-state transport in fermionic chains with long-range hopping
    S Sarkar, BK Agarwalla, DS Bhakuni
    Physical Review B 109, 165408 , 2024
    2024
    Citations: 14
  • Defect production and quench dynamics in the three-dimensional Kitaev model
    S Sarkar, D Rana, S Mandal
    Physical Review B 102 (13), 134309 , 2020
    2020
    Citations: 11
  • Time Crystals from single-molecule magnet arrays
    S Sarkar, Y Dubi
    ACS nano 18 (41), 27988–27996 , 2024
    2024
    Citations: 9
  • Environment-assisted and environment-hampered efficiency at maximum power in a molecular photocell
    S Sarkar, Y Dubi
    The Journal of Physical Chemistry C 124 (28), 15115–15122 , 2020
    2020
    Citations: 9
  • Protecting coherence from the environment via Stark many-body localization in a Quantum-Dot Simulator
    S Sarkar, B Buca
    Quantum 8, 1392 , 2024
    2024
    Citations: 8
  • Theoretical analysis of neutron scattering results for quasi-two dimensional ferromagnets
    S Sarkar, SK Paul, R Chaudhury
    The European Physical Journal B 85 (11), 380 , 2012
    2012
    Citations: 7
  • Bipartite particle number fluctuations in dephased long-range lattice systems
    L Tater, S Sarkar, DS Bhakuni, BK Agarwalla
    Physical Review B 112, 205407 , 2025
    2025
    Citations: 6
  • The spinterface mechanism for the chiral-induced spin selectivity effect: A Critical Perspective
    S Sarkar, A Sharoni, OLA Monti, Y Dubi
    ACS nano 19 (43), 37484-37503 , 2025
    2025
    Citations: 6
  • Ballistic vs. diffusive transport in metals
    Y Sivan, IW Un, S Sarkar
    arXiv preprint arXiv:2402.15226 , 2024
    2024
    Citations: 4
  • The connection between vortex-like topological excitations and conventional excitations in quantum ferromagnetic spin systems on two-dimensional lattice and their stability
    S Sarkar, R Chaudhury, SK Paul
    International Journal of Modern Physics B 29 (29), 1550209 , 2015
    2015
    Citations: 3
  • Quantum-optical theory of the few-femtosecond nonlinear optical response of Drude metals with a nonparabolic conduction band
    IW Un, S Sarkar, Y Sivan
    Physical Review B 113 (16), 165411 , 2026
    2026
    Citations: 1
  • The nonlinear optical response and electron dynamics in transparent conducting oxides
    IW Un, S Sarkar, Y Sivan
    2024 Conference on Lasers and Electro-Optics (CLEO), 1-2 , 2024
    2024
    Citations: 1
  • Fermi surface instabilities of symmetry-breaking and topological types on the surface of a three-dimensional topological insulator
    S Sarkar
    Physical Review B 98 (23), 235162 , 2018
    2018
    Citations: 1
  • Semi-phenomenological analysis of neutron scattering results for quasi-two dimensional quantum anti-ferromagnet
    S Sarkar, R Chaudhury, SK Paul
    Journal of Magnetism and Magnetic Materials 421, 207-215 , 2017
    2017
    Citations: 1