Gautam Gangopadhyay's homepage


My email address :-
gautam@boson.bose.res.in
 

                                                                           ..
 

Name: GAUTAM GANGOPADHYAY
 

e-mail:gautam@bose.res.in FAX: (91) (33) 2335 3477

Present Status:

Working as a Senior Professor at the S N Bose National Centre for Basic Sciences (SNBNCBS), Salt Lake City, Kolkata-700106.
 

Educational Qualifications: :
 

Ph.D.(Science)(1993) Jadavpur University(work done at Indian Association for the Cultivation of Sciences), India
M.Sc. (Chemistry, Physical Chemistry)(1985-1987) Burdwan University, India
B.Sc.(Chemistry Hons.)(1982-1985) Burdwan University, India
 

Broad Research Interest: :
 

i. Stochastic processes in Chemical and Biological Systems, specially interested in heterogeneous enzyme catalysis and ion-channel problems.
ii. Studies on quantum dynamics and quantum transport processes in molecular systems.
iii.Nonlinear dynamics and Reaction-diffusion systems in Chemistry and Biology.
 

List of Publications

110. Nonequilibrium thermodynamic Characterization of Chimeras in a Continuum Chemical Oscillator System,
P Kumar, G Gangopadhyay Physical Review E 105 (2022) 034208

109. Limit cycle for a generalized Lienard system beyond Lienard-Levinson-Smith(LLS) theorem,
S Saha, G Gangopadhyay Communications in Nonlinear Science and Numerical Simulation 86, (2022)

108. Universality in bio-rhythms; a perspective from nonlinear dynamics,
S. Saha, G. Gangopadhyay, D. S. Ray, Journal of Biosciences (Special issue), Springer 47 (2022) 0016.

107. Centre Manifold Analysis of 3-D nonlinear system and Kinetic stability of Protein Assembly
S Mazumdar and G Gangopadhyay Journal of Applied Nonlinear Dynamics, 11(1) (2022) 139–152

106. Nonequilibrium thermodynamics of glycolytic traveling wave: Benjamin-Feir instability
P Kumar, G Gangopadhyay Physical Review E 104 (2021), 014221

105. A Revisit to Turnover Kinetics of Individual Escherichia coli β-Galactosidase Molecules
P Kundu, S Saha, G Gangopadhyay The Journal of Physical Chemistry B 125 (2021) 11793

104. On the Role of Magnesium Ions in the DNA-Scissoring Activity of the Restriction Endonuclease ApaI: Stochastic Kinetics from a Single Molecule to Mesoscopic Paradigm,
Biswajit Das, Kinshuk Banerjee, and G Gangopadhyay The Journal of Physical Chemistry B 125, (2021) 4099–4107

103. Electron-Vibration Entanglement of Resonating Dimers in Quantum Transport
Anirban Karmakar and G Gangopadhyay The Journal of Physical Chemistry A 125, (2021), 3122–3134

102. Synchronization and metabolic energy consumption in stochastic Hodgkin-Huxley neurons: Patch size and drug blockers
K Pal, D Ghosh, G Gangopadhyay Neurocomputing 422, (2021) 222-234

101. Kinetics of Allosteric Inhibition of Single Enzyme by Product Molecules
P Kundu, S Saha, G Gangopadhyay The Journal of Physical Chemistry B 124 (2020) 11793

100. Parametric excitation and Hopf bifurcation analysis of a time delayed nonlinear feedback scoillator
S Saha, G Gangopadhyay, S Kumari, RK Upadhyay International Journal of Applied and Computational Mathematics 6 (2020), 1-21

99. An Exactly Solvable Stochastic Kinetic Theory of Single-Molecule Force Experiments
P Kundu, S Saha, G Gangopadhyay The Journal of Physical Chemistry B 124 (2020), 7735-7744

98. Suppressing birhythmicity by parametrically modulating nonlinearity in limit cycle oscillators
S Saha, S Chakraborty, G Gangopadhyay Physica D: Nonlinear Phenomena 416, (2020) 132793

97. Stochastic Kinetic Approach to the Escape of DNA Hairpins from an α-Hemolysin Channel
P Kundu, S Saha, G Gangopadhyay The Journal of Physical Chemistry B 124 (2020), 6575-6584

96. Termination of Action Potential Due to Site Selective Ion Channel Blockers K Pal, G Gangopadhyay
Fluctuation and Noise Letters 19 (2020), 2050015

95. Systematic designing of bi-rhythmic and tri-rhythmic models in families of Van der Pol and Rayleigh oscillators
S Saha, G Gangopadhyay, DS Ray Communications in Nonlinear Science and Numerical Simulation 85, (2020) 105234

94. Kinetics of escape of ssDNA molecules from α-hemolysin nanopores: a dynamic disorder study
P Kundu, S Saha, G Gangopadhyay Journal of Statistical Mechanics: Theory and Experiment 2020 (2020), 053501

93. Mechanical Unfolding of Single Polyubiquitin Molecules Reveals Evidence of Dynamic Disorder
P Kundu, S Saha, G Gangopadhyay ACS omega 5 (2020), 9104-9113

92. Energetic and entropic cost due to overlapping of Turing-Hopf instabilities in the presence of cross diffusion
P Kumar, G Gangopadhyay Physical Review E 101 (2020), 042204

91. The guiding role of dissipation in kinetic proofreading networks: Implications for protein synthesis
K Banerjee, B Das, G Gangopadhyay The Journal of Chemical Physics 152 (2020), 111102

90. MnO 2 flowery nanocomposites for efficient and fast removal of mercury (ii) from aqueous solution: a facile strategy and mechanistic interpretation
S Das, A Samanta, K Kole, G Gangopadhyay, S Jana Dalton Transactions 49 (2020) , 6790-6800.

89. Application of dynamic disorder approach to the temperature dependent non-exponential electron transfer kinetics in Rhodopseudomonas viridis
P Kundu, S Saha, G Gangopadhyay Journal of Statistical Mechanics: Theory and Experiment 2019 (9), 093501

88. A strong enhancement in electronic current due to conical-intersection
A Karmakar, G Gangopadhyay Physica Scripta 94 (2019), 125401

87. Reduction of Kinetic Equations to Liénard–Levinson–Smith Form: Counting Limit Cycles
S Saha, G Gangopadhyay, DS Ray International Journal of Applied and Computational Mathematics 5 (2019), 46

86. When an oscillating center in an open system undergoes power law decay
S Saha, G Gangopadhyay Journal of Mathematical Chemistry 57 (2019), 750-768

85. Clay-based nanocomposites as recyclable adsorbent toward Hg (II) capture: experimental and theoretical understanding
S Das, A Samanta, G Gangopadhyay, S Jana ACS omega 3 (2018), 6283-6292

84. Large deviation theory for the kinetics and energetics of turnover of enzyme catalysis in a chemiostatic flow
B Das, G Gangopadhyay The Journal of Chemical Physics 148 (2018), 174104

83**. Reduction of kinetic equations to Liénard-Levinson-Smith Form: Counting Limit Cycles,
S. Saha, G. Gangopadhyay and D. S. Ray, Int. J. Appl. Comput. Math., Springer, 5(2) (2019).

82*. Diffusion Influenced Non-equilibrium Gating Processes of a Voltage-gated Potassium Ion Channel
Biswajit Das, Gangopadhyay The Pharmaceutical and Chemical Journal, 2018, 5(2):144-166

81**. When an oscillating center in an open system undergoes power law decay,
S. Saha and G. Gangopadhyay, J. Math. Chem. 57, 750−768 (2018).

80*. Clay-Based Nanocomposites as Recyclable Adsorbent toward Hg(II) Capture: Experimental and Theoretical Understanding
S Das, A Samanta, G Gangopadhyay and S Jana ACS Omega 3, 6283−6292 (2018)

79**. Large deviation theory for the kinetics and energetics of turn over of enzyme catalysis in a chemiostatic flow
Biswajit Das and Gautam Gangopadhyay J Chem. Phys. 148, 174104 (2018)

78*. Isochronicity and limit cycle oscillation in biochemical system,
Sandip Saha and Gautam Gangopadhyay, J. Math. Chem. 55 (3), 887-910 (2017).

77**. Nonequilibrium response of a voltage gated sodium ion channel and biophysical characterization of dynamic hysteresis,
K Pal, B Das and G Gangopadhyay, J.Theo. Biol. 21;415:113-124 (2017).

76*. Dynamical characterization of inactivation path in voltage-gated Na+ ion channel by non-equilibrium response spectroscopy,
Krishnendu Pal, Gautam Gangopadhyay, Channels, 10 (6): 478-497 (2016).

75**. Fermionic thermocoherent state: Efficiency of electron transport,
Anirban Karmakar and Gautam Gangopadhyay, Phys. Rev. E 93, 022141 (2016).

74*. Kinetics and Entropy Production of Force-induced Oligomeric Enzyme Catalysis in a Single Trajectory: Effect of Multiple Substrates,
Gangopadhyay, Biswajit Das, Kinshuk Banerjee and Gautam Gangopadhyay, American Chemical Science Journal, 8 (4):2249-0205 (2015).

73**. Nonequilibrium thermodynamics and a fluctuation theorem for individual reaction steps in a chemical reaction network,
Krishnendu Pal, Biswajit Das, Kinshuk Banerjee and G Gangopadhyay, Journal of Physics: Conference Series 638 (2015) 012002.

72*. Probing kinetic drug binding mechanism in voltage-gated sodium ion channel: open state versus inactive state blockers,
Krishnendu Pal, Gautam Gangopadhyay, Channels, 9(5):307-16 (2015).

71*. Characterization of conical intersection in a cis- trans isomerization through nonclassicality and entanglement,
Kinshuk Banerjee, Gautam Gangopadhyay, Journal of Math. Chem., 53 (8):1733-1749 (2015).

70*. A Noisy Nutrient Inducd Instability in Phytoplankton Blooms
T K D, A G and G Gangopadhyay Int. J. Curr. Res. Acad. Rev. 2015 Vol. 3, 51-59

69*. Comparison of electromagnetically induced transparency in lambda, cascade and vee three-level systems
Surajit Sen, Tushar Kanti Dey, Mihir Ranjan Nath and Gautam Gangopadhyay Journal of Modern Optics, 2015 Vol. 62, 166–174.

68*. A fermionic bath induced antibunching and coherence in Mollow spectra
A. Karmakar and G. Gangopadhyay, Physica Scripta 89 (2014) 45001.

67. Propensity approach to nonequilibrium thermodynamics of a chemical reaction network: Controlling single E-coli beta-galactosidase enzyme catalysis through the elementary reaction steps,
B. Das, K. Banerjee and G. Gangopadhyay, J. Chem. Phys. 139 (2013) 244104.

66. Emission Rate, Vibronic Entanglement and Coherence in Aggregates of Conjugated Polymers,
K. Banerjee and G. Gangopadhyay, J. Phys. Chem. A 117 (2013) 8642-8650.

65. Realization of vibronic entanglement in terms of tunneling current in an artificial molecule,
K. Banerjee and G. Gangopadhyay, J. Math. Chem. 51 (2013) 2731-2745.

64. On the estimation of cooperativity in ion channel kinetics: activation free energy and kinetic mechanism of potassium ion channel,
K Banerjee, B Das and G Gangopadhyay, J. Chem. Phys. 138,(2013) 165102.

63. Entropy production of a mechanically driven single oligomeric enzyme: a consequence of fluctuation theorem,
B. Das, K. Banerjee and G. Gangopadhyay, J. Math. Chem.51, (2013) 588.

62. Entropy hysteresis and nonequilibrium thermodynamic efficiency of ion conduction in a voltage-gated potassium ion-channel,
B. Das, K. Banerjee and G. Gangopadhyay, Phys. Rev. E 86, (2012) 061915.

61. Entropic estimate of cooperative binding of substrate on a single oligomeric enzyme: An index of cooperativity,
K. Banerjee, B. Das and G. Gangopadhyay, J. Chem. Phys. 136 (2012) 154502.

60. Decoherence without dissipation due to fermionic bath,
A. Karmakar and G. Gangopadhyay, Physica Scripta 85 (2012) 045008.

59. Electronic nuclear entanglement in a conjugated polymer aggregate with a conical intersection: spectral signatures
K. Banerjee and G. Gangopadhyay, J. Phys.B 45 (2012) 045102.

58. Stochastic theory of interfacial enzyme kinetics: A kinetic Monte Carlo study,
B. Das and G. Gangopadhyay, Chem. Phys. 393 (2012) 58.

57. Bloch space structure, the qutrit wave function and atom-field entanglement in three-level systems,
S. Sen, M. R. Nath, T. K. dey and G. Gangopadhyay, Annals of Physics 327 (2012) 224.

56. Magnetically induced variation of tunneling current and nonclassicality in a coupled quantum dot system,
K. Banerjee and G. Gangopadhyay, AIP Conf. Proc. 1384 (2011) 137.

55. Bloch equation and atom-field entanglement scenario in three-level systems,
S. Sen, M. R. Nath, T. K. dey and G. Gangopadhyay, AIP Conf. Proc. 1384 (2011) 190.

54. Role of positional disorder in the spectra of conjugated polymer aggregates: conical intersection of potential energy surfaces
K. Banerjee and G. Gangopadhyay, J. Phys.B 43 (2010) 235104.

53. Master equation approach to single oligomeric enzyme catalysis: Mechanically controlled further catalysis,
B. Das and G. Gangopadhyay, J. Chem. Phys. 132 (2010) 135102.

52. Effect of geometry of dipolar orientations on the spectra of di and trimer chain aggregates.
K. Banerjee and G. Gangopadhyay, Phys. Rev. B 81 (2010) 035307.

51. Aggregate of a network of conjugated polymer chains: Symmetry of the excitonic states and spectral features,
K. Banerjee and G. Gangopadhyay, J. Phys.B 42 (2009) 165106.

50. Spectra of conjugated polymer aggregates: Symmetry of the interchain dressed states,
K. Banerjee and G. Gangopadhyay, J. Chem. Phys. 130 (2009) 084705.

49. Dynamical symmetry breaking of lambda and vee-type three-level systems on quantization of the field modes,
M R Nath, S Sen, A K Sen and G. Gangopadhyay,, Pramana- J. Phys.71 (2008)77.

48. Effect of field quantization on Rabi oscillation of equidistant cascade four-level system,
M R Nath, T K Dey, S Sen and G. Gangopadhyay,, Pramana- J. Phys.70 (2008) 141.

47. Quantum electron transfer processes induced by thermocoherent state,
S. Banerjee and G. Gangopadhyay, J. Chem. Sciences 119 (2007) 1-10.

46. On the microscopic basis of Newton's law of cooling and beyond,
M R Nath, S Sen and G. Gangopadhyay, J. Chem. Phys. 127 (2007) 094505.

45. On the quantum theory of electron transfer: effect of potential surfaces of the reactant and product,
S. Banerjee and G. Gangopadhyay, J. Chem. Phys. 126 (2007) 034102.

44. Theoretical studies of electron transfer through dendrimer architecture,
D. Rana and G. Gangopadhyay, J. Chem. Phys. 124 (2006) 044909.

43. Laser cooling of vibrational degrees of freedom of a molecular system,
S. Banerjee and G. Gangopadhyay, J. Chem. Phys. 123 (2005) 114304.

42. The absorption bandshape function of a molecule from a thermocoherent state and some associated multilinear generating-function relationships for Laguerre polynomials,
H. M. Srivastava and G. Gangopadhyay, Russ. J. Math. Phys. 11 (2004) 359-367.

41. Radiative Decay of Nonstationary System ,
S. Banerjee and G. Gangopadhyay, J. Chem. Phys. 120 (2004) 6152.

40. Born-Oppenheimer approximation: A Toy version,
G Gangopadhyay and B. Dutta-Roy, Am. J. Phys. 72 (2004) 389.

39. Dynamics of cascade three level system interacting with the classical and quantized field,
M R Nath,S Sen and G Gangopadhyay, Pramana-J. Phys. 61 (2003) 1089-1100.

38. Quantum beat in pump-probe signal of molecular system,
S. Banerjee and G. Gangopadhyay, J. Phys. B 36 (2003) 2967.

37. Power law relaxation kinetics in reversible enzyme-catalyzed reaction due to diffusion,
S. Paul and G. Gangopadhyay, J. Chem. Phys. 119(2003) 3501.

36. Power law relaxation kinetics in multistate reversible reaction,
S. Paul and G. Gangopadhyay, Chem. Phys. Letts. 369 (2003) 643.

35. Studies on energy transfer in Dendrimer supermolecule using classical random walk model and Eyring model,
D. Rana and G. Gangopadhyay, J. Chem. Phys. 118 (2003) 434.

34. Spectra of displaced distorted oscillator molecular system ,
S. Banerjee and G. Gangopadhyay, Chem. Phys. Letts. 359 (2002) 295.

33. On dissipationless decoherence ,
G. Gangopadhyay, M. Sanjay Kumar and S. Dattagupta, J. Phys. A 34 (2001) 5485.

32. Steady state spectral properties of dendrimer supermolecules as light harvesting system,
D. Rana and G. Gangopadhyay, Chem. Phys. Letts. 314 (2001) 324.

31. An operator approach to the construction of generating function for the product of Laguerre Polynomials: A thermal average bandshape function of a molecule,
G Gangopadhyay, J. Phys. A Math. & Gen. 32 (1999) L441.

30. A thermal bath induced new resonances in linear and nonlinear spectra of a two-level system,
G Gangopadhyay, S Ghoshal and Y Tanimura, Chem. Phys. 242 (1999) 367.

29. A generating function for the product of Laguerre polynomials: Franck-Condon factor for multiphoton processes,
G Gangopadhyay, J. Phys. A Math. & Gen. 31 (1998) L771.

28. Theory of non-stationary activated rate processes: non-exponential kinetics, J Ray Chaudhuri, G Gangopadhyay and D S Ray, J. Chem. Phys 109 (1998) 5565.

27. Quantum Theory of dissipation of a harmonic oscillator coupled to a non-equilibrium bath; Wigner-Weisskopf decay and Physical Spectra, J Ray Chaudhuri, B Deb, G Gangopadhyay and D S Ray, J. Phys. B 31 (1998) 3859.

26. Absorption line shape of impurity molecule driven by a fractal noise,
G Gangopadhyay and Y Tanimura, Chem. Phys. Letts. 289 (1998) 97.

25. A thermal bath induced Rabi splitting on the profile of Mollow spectrum in single molecule spectroscopy,
G Gangopadhyay and S Ghoshal Chem. Phys. Letts 289 (1998) 287.

24. The effect of environment induced pure dephasing in the generalized Jaynes-Cummings model,
G Gangopadhyay and S H Lin, Pramana- J. Phys. 49 (1997) 399.

23. The effect of environment induced pure dephasing in the Jaynes-Cummings model,
G Gangopadhyay and S H Lin, Physica Scripta 55 (1997) 425.

22. Theory of Quantum fluctuations in classically chaotic Hamiltonian systems, S Chaudhuri, G Gangopadhyay and D S Ray, Phys. Rev E54 (1996)53

21. Field induced quantum barrier crossing; classical chaos and weak localization, S Chaudhuri, G Gangopadhyay and D S Ray, Phys.Letts. A216 (1996) 53.

20. Signature of Classical chaos on field induced quantum barrier crossing, S Chaudhuri, G Gangopadhyay and D S Ray, Special issue on Complex systems, Indian Journal of Physics, 69B (1995)507.

19. The non-Markovian master equation for stochastically perturbed systems; effect on spectral lineshape, G Gangopadhyay and D S Ray, J. Mol. Struc.(Theo Chem), 361 (1996) 49.

18. Population trapping in the Jaynes-Cummings model with a kerr nonlinear medium,
A Bandyopadhyay and G Gangopadhyay , J. Mod. Opt. 43 (1996) 487.

17. Fluctuation and decoherence in classical chaos: A model study of a Kubo oscillator generated by a chaotic system, S Chaudhuri, G Gangopadhyay and D S Ray, Phys. Rev. E52 (1995) 2262.

16. Generation of a class of arbitrary two-mode field state in a cavity, B. Deb, G Gangopadhyay and D.S. Ray, Phys. Rev. A 51 (1995) 2651.

15. Coherent phase state and displaced phase state in a finite dimensional basis and their light field limits,
G Gangopadhyay, J. Mod. Opt. Vol 41 (1994) 525.

14. Master equation in quantum optics; some generalizations, G Gangopadhyay and D S Ray, in Advances in Multiphoton Processes, edited by S H Lin, A A Villaeys and F Fujimura, World Scientific, Singapur, 1993.

13. Population trapping in a Raman-coupled model interacting with a two-mode quantized cavity fields, B Deb, G Gangopadhyay and D S Ray, Phys. Rev. A 48 (1993) 1400.

12. A fluctuation-diffusion relation in chaotic dynamics,
S Chaudhuri,G Gangopadhyay and D S Ray, Phys.Rev.E 47 (1993)311

11. Cavity field-assisted atomic relaxation and suppression of resonance fluorescence at high intensities,
G Gangopadhyay, S Basu and D S Ray, Phys. Rev. A 47 (1993) 1314

10. Non-Markovian master equation for linear and nonlinear systems,
G Gangopadhyay and D S Ray, Phys. Rev. A 46 (1992) 1507

9. A master equation approach to multiphoton dissociation of Morse oscillator,
G Gangopadhyay and D S Ray, J. Chem. Phys. 97 (1992) 4104

8. Master equation for nonlinear dissipative systems, G Gangopadhyay and D S Ray, J. Chem. Phys. 96 (1992) 4693

7. Cavity QED with a single Morse oscillator, G Gangopadhyay and D S Ray, in Quantum Optics edited by R Inguva (PlenumPress, N. Y. 1992)

6. Spectral modification of the Stokes line of a Raman-coupled three level system in a cavity,
G Gangopadhyay and D S Ray, Phys. Rev. A 45 (1992) 1843

5. Master equation for dissipative dynamics of a two-level atom in a superintense field; field dependent relaxation,
G Gangopadhyay and D S Ray, Phys. Rev. A 44 (1991) 2206

4. Quantum electrodynamics of a single Morse oscillator in a cavity; spectral aspects,
G Gangopadhyay and D S Ray, Phys. Rev. A 43 (1991) 6424

3 Power spectra of light scattered from a strongly driven Morse oscillator,
G Gangopadhyay and D S Ray, Phys. Rev. A 41 (1990) 6429

2. Spectra of four-wave mixing in a self-consistent field,
G Gangopadhyay and D S Ray, Phys. Rev. A 41 (1990) 3985

1. A global stochasticity criteria for Maxwell-Bloch equation,
G Gangopadhyay and D S Ray, Phys. Rev. A 40 (1989) 3750
 

Summary of research activities in last few years by Prof. Gautam Gangopadhyay


 

1. Research interest:


 

*. Nonlinear nonequilibrium dynamics in Chemical and Biological systems *. Stochastic processes in Complex systems *. Quantum transport in molecular and Biological processes.


 

2. Some highlights about most important research achievement are as follows:


 

(i). Exploration of the energetic and entropic cost due to Turing and Hopf instabilities in nonlinear open system (ii). Investigation of the role of entropy production in kinetic proof reading in chemical network (iii) Devising a single molecule approach to deal with the dynamic disorder in various chemical and biological processes


 

3. Nature of our works on some specific projects are as follows:


 

a. Multiscale dynamics in open Chemical and Biological Systems: The self-sustained chemical oscillations are regularly observed in biological world to maintain a cyclic steady state e.g., cell division, circadian oscillation, calcium oscillations and other bio-systems. Our aim in this project is to look into the physical and mathematical properties of weakly nonlinear systems containing periodic orbits by adopting various methods of multiscale perturbation analysis to cover single to multi-limit cycles which can arise in various practical situations. We have presented an unified scheme to express a class of system of equations in two variables into a Liénard - Levinson -Smith(LLS) oscillator form. We have derived the condition for limit cycle for arbitrary polynomial functions of damping and restoring force. A method is devised to determine the maximum number of limit cycles admissible for a LLS oscillator. Based on this approach we proposed a scheme for systematic designing of generalised Rayleigh and Van der Pol families of oscillators with a desired number of multiple limit cycles.


 

b. Dynamic disorder and conformational fluctuations in reaction kinetics: The decay of the nonexponential kinetics at the microsecond timescale, points to the relevance of having possible influence of dynamic disorder on the reaction kinetics. To rationalize the experimental results by the microscopic dynamics of protein a molecule are described in terms of the anomalous diffusion of a Brownian particle in a harmonic potential well under the action of fractional Gaussian noise.


 

c. Quantum transport through molecular system: To construct the theory of quantum transport through molecular system we have developed the formulation of quantum system coupled to a fermionic bath and the model is applied in various coherent processes. In continuation of our earlier work we have studied the electronic and nuclear entanglement with nonadiabatic effects in conical intersection regime.
 

A. Area of research and descriptions of problems:
  Summary of research work of Gautam Gangopadhyay: Areas of Research: Chemical Physics. During the period, (2014-2019) we have worked broadly in the following four projects


 


 

1. Molecular quantum Dynamics and Quantum transport:

To construct the theory of quantum transport through molecular system we have developed the formulation of quantum system coupled to a fermionic bath and the model is applied in various coherent processes. In continuation of our earlier work we have studied the electronic and nuclear entanglement with nonadiabatic effects.


 

On the fermionic thermocoherent state: efficiency of electron transport

On the basis of the fermionic coherent state of Cahill and Glauber[(1999), Phys. Rev. A, we have introduced here fermionic thermocoherent state in terms of the quasiprobability distribution which shows the appropriate thermal and coherent limits as in the bosonic case or Glauber-Lachs state. It is shown that the fermionic thermocoherent state can be realised as a displaced thermal state of fermions. Its relation with the fermionic displaced number state and fermion-added coherent state are explored in the spirit of bosonic case. We have investigated the nature of the average current and the suppression of noise due to thermocoherent character of the source. The theory is applied to the problem of electronic conduction. A modification of Landauer conductance formula is suggested which reflects the role of nonzero coherence of the source in electron transport.


 

Electron transport through molecular system: a master equation approach

Based on the formulation of quantum master equation for fermionic bath, we have estimated electron transport through a molecular system which is coupled to two electron leads with a vibrational manifold. The molecular current is studied as a function of external and internal bias and the differential conductance is studied against the external bias. We have also calculated the Fano factor as a measure of current noise. Numerical results for pyridine molecule as a system shows that electron-phonon coupling can be an indicator of current noise which can suppress molecular current. An additional electron transport channel through electron-phonon coupling gives rise to a vibration induced Coulomb blockade which can be used as a marker of vibrational modes of the system.

In a similar context we have shown a strong enhancement in electronic current due to conical-intersection in the molecular system undergoing a cis-trans isomerization. Publications: 68*. A fermionic bath induced antibunching and coherence in Mollow spectra A. Karmakar and G. Gangopadhyay, Physica Scripta 89 (2014) 45001. 72*. Characterization of conical intersection in a cis- trans isomerization through nonclassicality and entanglement, Kinshuk Banerjee, Gautam Gangopadhyay, Journal of Math. Chem., 53 (8):1733-1749 (2015). 75**. Fermionic thermocoherent state: Efficiency of electron transport, Anirban Karmakar and Gautam Gangopadhyay, Phys. Rev. E 93, 022141 (2016). 86**. A strong enhancement in electronic current due to conical-intersection Anirban Karmakar and Gautam Gangopadhyay Physica Scripta(Accepted) 92*. Electron transport through molecular system: a master equation approach Anirban Karmakar and Gautam Gangopadhyay (submitted)


 

2. Multiscale nonlinear dynamics in open Chemical and Biological Systems

Chemical oscillations show non-linear dynamical phenomenon which can be understood in terms of the stability of non-equilibrium steady state of a reaction within far away from equilibrium condition. Experimentally such open systems like, Bray, BZ and glycolytic reactions are studied extensively in a continuously flowing stirred tank reactor and the nature of the oscillatory kinetics of two intermediates gave reliable dynamical models of limit cycle. The self-sustained chemical oscillations are also regularly observed in biological world to maintain a cyclic steady state e.g., cell division[, circadian oscillation, calcium oscillations and other bio-systems. The generic feature of such diverse nature of non-linear oscillations are due to auto-catalysis and various feedback mechanisms into the system which are basically controlled by a few slow time scales of the overall process. Such periodic orbits can be isochronous or the frequency may depend on their amplitude of which the most common examples of periodic orbits of open systems are limit cycle and in some special cases they become center like in a harmonic oscillator. The ubiquity of limit cycle in dynamical system described by a pair of ordinary differential equations are quite characterised mathematically, however, a general prescription of shape, size and the number of stable limit cycles in a given system are not yet well established. From the physical point of view the response properties of a limit cycle due to an external driving field is also ill understood unlike ordinary oscillations in various physical processes. On the one hand there is a challenge in dealing with limit cycles in a strongly nonlinear systems inspite of several developments of various multiscale perturbation techniques like, Krylov-Boguliobov(K-B) method, Poincare-Linstedt method[, Renormalization Group(RG) method etc. On the other hand a limit cycle in a given dynamical system of phenomenological importance can be a great tool as the nature is playing through various stable limit cycles to regulate its self organized processes which need to be understood.

Our aim in this project is to look into the physical and mathematical properties of weakly nonlinear systems containing periodic orbits by adopting various methods of multiscale perturbation analysis to cover single to multi-limit cycles which can arise in various practical situations. More specifically we consider a class of open natural dynamical systems in the form of an oscillator of generalised Liénard equation which is utilised to study the chacterisation of various periodic orbits. In order to understand the response properties of limit cycle under external perturbation we have investigated subharmonic resonances. As the multiple limit cycle in a given system is an important issue here we have explored on the counting of limit cycles and its application in systematic construction of birhythmic and tri-rhythmic oscillators from a simple limit cycle system. As the diffusion is an integral part of the most dynamical systems in chemical and biological context we have studied reaction-diffusion systems which effectively creates a spatial inhomogeneity by adding a slower time scale in the system dynamics. In presence of diffusion, for a system of limit cycle we have investigated the diffusion driven instability through the construction of amplitude and phase equations in spatio-temporal pattern. Publications: 78*. Isochronicity and limit cycle oscillation in biochemical system, Sandip Saha and Gautam Gangopadhyay, J. Math. Chem. 55 (3), 887-910 (2017). 82**. When an oscillating center in an open system undergoes power law decay, S. Saha and G. Gangopadhyay, J. Math. Chem., 57 (3), 750−768 (2018). 83**. Reduction of kinetic equations to Liénard-Levinson-Smith Form: Counting Limit Cycles, S. Saha, G. Gangopadhyay and D. S. Ray, Int. J. Appl. Comput. Math., Springer, 5(2) (2019). 88*. Hopf bifurcation analysis of a time delayed nonlinear feedback oscillator, S. Saha, G. Gangopadhyay, S. Kumari and R. K. Upadhyay. (submitted) 89*. A recipe for construction of multirhythmic models in van der Pol and Rayleigh family of oscillators, S. Saha and G. Gangopadhyay and D. S. Ray. (Submitted)


 

3. Nonequilibrium Features Of Voltage Gated Sodium Ion Channel

The research on the voltage-gated sodium ion channel draws immense attention in neuroscience as they are targeted for anesthesia and treatments for genetic diseases in brain, muscle and heart etc. The Sodium ion channel initiates the action potential, the most essential requirement for communication between cells. We have investigated the nonequilibrium kinetic and thermodynamic responses of sodium ion channel using Nonequilibrium Response Spectroscopy(NRS) where a continuous supply of energy takes place in to the system from external sources using oscillating or fluctuating or pulsed voltage protocol which forces the ion channel to stay in non equilibrium situation.

The particular works done are briefly given below: (a) Using oscillating external voltage protocol we have studied the dynamic hysteresis at nonequilibrium steady state and its parametric dependence(e.g. frequency, amplitude, mean voltage) of external voltage protocol. The work done for overall gating dynamics is estimated by calculated the loop area of total entropy production rate. The utilization of energy and associated dissipative work done at nonequilibrium steady state is also estimated. (b) We have shown that open state drug blocking is a free energy driven process while closed state blocking is an entropy driven process. Comparing all voltage protocols we concluded that inactive state blockers are more potent channel blockers than open state blockers. (c) Next we switched our study from single channel to the whole cell Hodgkin-Huxley neuron. Modifying existing Hodgkin-Huxley model with sodium as well as potassium drug bound states and using Gillespie's exact Markov simulation technique a more realistic picture of drug binding is obtained.(d) Finally we have extended our study from one neuron to two neurons, unidirectionally coupled via electrical synapses. We have shown that the size of patch/channel number fluctuations in individual neurons have very important role in unidirectional synchronization and metabolic energy consumption. The effect of sodium, potassium blockers have very interesting and distinct effect on synchronization process and metabolic energy consumption. Publications: 73*. Probing kinetic drug binding mechanism in voltage-gated sodium ion channel: open state versus inactive state blockers, Krishnendu Pal, Gautam Gangopadhyay, Channels, 9(5):307-16 (2015). 76*. Dynamical characterization of inactivation path in voltage-gated Na+ ion channel by non-equilibrium response spectroscopy, Krishnendu Pal, Gautam Gangopadhyay, Channels, 10 (6): 478-497 (2016). 77**. Nonequilibrium response of a voltage gated sodium ion channel and biophysical characterization of dynamic hysteresis, Krishnendu Pal, Biswajit Das and Gautam Gangopadhyay, J.Theo. Biol. 21;415:113-124 (2017). 81*. Diffusion Influenced Non-equilibrium Gating Processes of a Voltage-gated Potassium Ion Channel Biswajit Das, Gangopadhyay The Pharmaceutical and Chemical Journal, 2018, 5(2):144-166 85*. Termination Of Action Potential Due To Site Selective Ion Channel Blockers Krishnendu Pal and Gautam Gangopadhyay Fluctuation and Noise Letters World Scientific(Accepted)


 

4. Kinetics and nonequilibrium thermodynamics of enzyme catalysis:

Large deviation theory for the kinetics and energetics of turn over of enzyme catalysis in a chemiostatic flow In the framework of large deviation theory we have characterized nonequilibrium turn over statistics of enzyme catalysis in a chemiostatic flow with externally controllable parameters, like substrate injection rate and mechanical force. In kinetics of the process we have shown the fluctuation theorems in terms of the symmetry of the scaled cumulant generating function(SCGF) in transient and steady state regime and similar symmetry rule is reflected in large deviation rate function(LDRF) as a property of the dissipation rate through boundaries. Large deviation theory also gives the thermodynamic force of nonequilibrium steady state(NESS), as is usually recorded experimentally by single molecule technique, which plays a key role responsible for the dynamical symmetry of the SCGF and LDRF. Using some special properties of Legendre transformation here we have provided a relation between the fluctuations of fluxes and dissipation rates and among them the fluctuation of turn over rate is routinely estimated but the fluctuation in dissipation rate is yet to be characterized for small systems. Such an enzymatic reaction flow system can be a very good testing ground to systematically understand the rare events from the large deviation theory which is beyond fluctuation theorem and central limit theorem.

Effect of Diffusion of Substrates on the Non-Equilibrium Turnover of Single Oligomeric Enzyme Catalysis Here we have shown how to account for the effect of substrate diffusion in single oligomeric enzyme kinetics with chemiostatic condition. We have provided a master equation based formulation of reaction-diffusion dynamics of enzyme catalysis in nonequilibrium state where the diffusion of substrates affect the conformational dynamics of oligomeric enzyme. As the nonequilibrium total entropy production rate(epr) can give the information of both the kinetic and temporal profile of energetics of the process, here we have systematically shown the results both in the reaction controlled and diffusion controlled regimes. In a similar context dynamic disorder is studied in electron transfer in single molcule enzyme and mechanical unfolding of single poly-ubiquitin molecule. Publications: 74*. Nonequilibrium thermodynamics and a fluctuation theorem for individual reaction steps in a chemical reaction network, Krishnendu Pal, Biswajit Das, Kinshuk Banerjee and G Gangopadhyay, Journal of Physics: IOP Conf. Ser. 638 (2015) 012002. 79**. Large deviation theory for the kinetics and energetics of turn over of enzyme catalysis in a chemiostatic flow Biswajit Das 1 and Gautam Gangopadhyay J Chem Phys. 148, 174104 (2018) 84*. Thermodynamic versus Kinetic Discrimination of Cooperativity of Enzymatic Ligand Binding, Biswajit Das, Kinshuk Banerjee and G Gangopadhyay,Austin Biochemistry - Volume 4 Issue 1 – 2019 93*. Application of dynamic disorder approach to the temperature dependent non-exponential electron transfer kinetics in Rhodopseudomonas viridis, Prasanta Kundu, Soma Saha and G. Gangopadhyay, J. Stat, Mech. Theo. Expt. 1742-5468 (2019). 94*. Mechanical unfolding of single poly-ubiquitin molecules reveals evidence of dynamic disorder Prasanta Kundu, Soma Saha, and Gautam Gangopadhyay (submitted)


 

Research Output (a) Published in Peer-Reviewed Journals : (Papers written during the tenure as Professor(2014-2019)

68*. A fermionic bath induced antibunching and coherence in Mollow spectra A. Karmakar and G. Gangopadhyay, Physica Scripta 89 (2014) 45001. 69*. Comparison of electromagnetically induced transparency in lambda, cascade and vee three-level systems Surajit Sen, Tushar Kanti Dey, Mihir Ranjan Nath and Gautam Gangopadhyay Journal of Modern Optics, 2015 Vol. 62, 166–174. 70*. A Noisy Nutrient Inducd Instability in Phytoplankton Blooms T K D, A G and G Gangopadhyay Int. J. Curr. Res. Acad. Rev. 2015 Vol. 3, 51-59 71*. Characterization of conical intersection in a cis- trans isomerization through nonclassicality and entanglement, Kinshuk Banerjee, Gautam Gangopadhyay, Journal of Math. Chem., 53 (8):1733-1749 (2015). 72*. Probing kinetic drug binding mechanism in voltage-gated sodium ion channel: open state versus inactive state blockers, Krishnendu Pal, Gautam Gangopadhyay, Channels, 9(5):307-16 (2015). 73**. Nonequilibrium thermodynamics and a fluctuation theorem for individual reaction steps in a chemical reaction network, Krishnendu Pal, Biswajit Das, Kinshuk Banerjee and G Gangopadhyay, Journal of Physics: Conference Series 638 (2015) 012002. 74*. Kinetics and Entropy Production of Force-induced Oligomeric Enzyme Catalysis in a Single Trajectory: Effect of Multiple Substrates, Gangopadhyay, Biswajit Das, Kinshuk Banerjee and Gautam Gangopadhyay, American Chemical Science Journal, 8 (4):2249-0205 (2015). 75**. Fermionic thermocoherent state: Efficiency of electron transport, Anirban Karmakar and Gautam Gangopadhyay, Phys. Rev. E 93, 022141 (2016). 76*. Dynamical characterization of inactivation path in voltage-gated Na+ ion channel by non-equilibrium response spectroscopy, Krishnendu Pal, Gautam Gangopadhyay, Channels, 10 (6): 478-497 (2016). 77**. Nonequilibrium response of a voltage gated sodium ion channel and biophysical characterization of dynamic hysteresis, K Pal, B Das and G Gangopadhyay, J.Theo. Biol. 21;415:113-124 (2017). 78*. Isochronicity and limit cycle oscillation in biochemical system, Sandip Saha and Gautam Gangopadhyay, J. Math. Chem. 55 (3), 887-910 (2017). 79**. Large deviation theory for the kinetics and energetics of turn over of enzyme catalysis in a chemiostatic flow Biswajit Das and Gautam Gangopadhyay J Chem. Phys. 148, 174104 (2018) 80*. Clay-Based Nanocomposites as Recyclable Adsorbent toward Hg(II) Capture: Experimental and Theoretical Understanding S Das, A Samanta, G Gangopadhyay and S Jana ACS Omega 3, 6283−6292 (2018) 81**. When an oscillating center in an open system undergoes power law decay, S. Saha and G. Gangopadhyay, J. Math. Chem. 57, 750−768 (2018). 80*. Diffusion Influenced Non-equilibrium Gating Processes of a Voltage-gated Potassium Ion Channel Biswajit Das, Gangopadhyay The Pharmaceutical and Chemical Journal, 2018, 5(2):144-166 83**. Reduction of kinetic equations to Liénard-Levinson-Smith Form: Counting Limit Cycles, S. Saha, G. Gangopadhyay and D. S. Ray, Int. J. Appl. Comput. Math., Springer, 5(2) (2019). 84*. Thermodynamic versus Kinetic Discrimination of Cooperativity of Enzymatic Ligand Binding, Biswajit Das, Kinshuk Banerjee and G Gangopadhyay, Austin Biochemistry - Volume 4 Issue 1 - 20196 85*. Termination Of Action Potential Due To Site Selective Ion Channel Blockers Krishnendu Pal and Gautam Gangopadhyay Fluctuation and Noise Letters World Scientific(Accepted) 86**. A strong enhancement in electronic current due to conical-intersection Anirban Karmakar and Gautam Gangopadhyay Physica Scripta(Accepted) Papers Communicated: 87*. Effect of Channel Noise in Synchronization and Metabolic Energy Consumption in Unidirectionally Coupled Neurons: Drug Blocking of Sodium and Potassium Channels Krishnendu Pal, Gautam Gangopadhyay(submitted) arXiv:1810.04381 [physics.bio-ph] 88*. Hopf bifurcation analysis of a time delayed nonlinear feedback oscillator, S. Saha, G. Gangopadhyay, S. Kumari and R. K. Upadhyay. (submitted) 89*. A recipe for construction of multirhythmic models in van der Pol and Rayleigh family of oscillators, S. Saha and G. Gangopadhyay and D. S. Ray. (Submitted) 90*. Oscillating resonances in parametrically excited limit cycle, S. Saha, S. Chakraborty and G. Gangopadhyay. 91*. Amplitude equation for Reaction-Diffusion system and traveling waves in glycolysis, S. Saha, P. Kumar and G. Gangopadhyay. 92*. Electron transport through molecular system: a master equation approach Anirban Karmakar and Gautam Gangopadhyay (submitted) 93*. Application of dynamic disorder approach to the temperature dependent non-exponential electron transfer kinetics in Rhodopseudomonas viridis, Prasanta Kundu, Soma Saha, and Gautam Gangopadhyay J. Stat, Mech. Theo. Expt. 1742-5468 (2019). 94*. Mechanical unfolding of single poly-ubiquitin molecules reveals evidence of dynamic disorder Prasanta Kundu, Soma Saha, and Gautam Gangopadhyay (submitted) 95. Energetic and entropic cost due to overlapping of Turing-Hopf instabilities in the presence of cross diffusion Premashis Kumar and Gautam Gangopadhyay, PHYSICAL REVIEW E 101, 042204 (2020) 96. The guiding role of dissipation in kinetic proofreading networks: Implications for protein synthesis, Kinshuk Banerjee, Biswajit Das and Gautam Gangopadhyay, J. Chem. Phys. 152, 111102 (2020)