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Assistant Professor
BS/MS IIT Kanpur
Ph.D. Chemical Physics,
University of Colorado, Boulder
Email: vivektiwari@iisc.ac.in

Welcome to Multidimensional Spectro-Imaging Group  [‘musig‘]

Gaining a fundamental understanding of the quantum dynamics of energy and charge transfer is key for any scalable technology based on new photovoltaic and optoelectronic materials. Such materials may include organic polymers and singlet fission materials, inorganic perovskites, quantum dots and layered 2D materials. Key design principles, such as exploiting quantum coherence or vibronic mixing to enhance function in artificial light-harvesting systems, could also be learned by probing the quantum dynamics of light-harvesting in natural photosynthetic proteins.

Coupled vibrational-electronic motions on femtosecond timescales and nanometer lengthscales play a central role in initiating energy and charge transfer dynamics in the above systems. Our group develops state-of-the-art coherent multidimensional spectroscopic techniques and quantum dynamical models to understand how ultrafast vibrational-electronic motions can delocalize energy and charge on the nanoscale.

Typically all projects in our group involve a strong overlap of experimental and theoretical components. Such components include – time-dependent quantum mechanics and spectroscopy, quantum dynamics of open quantum systems, nonlinear optics and electronics, advanced data processing techniques such as fast Fourier transforms, sparse sampling, etc.

Please go over our recent publications for a flavor of the kind of experimental and theoretical work carried out in the group. Visit our homepage or our laboratory to know more about our current directions. In case you are interested in joining our group, please email me your CV along with your research interests.

  1. Sanjoy Patra and Vivek Tiwari, “Vibronic Resonance Along Effective Modes Mediates Selective Energy Transfer in Excitonically Coupled Aggregates”, J. Chem. Phys. (2022), Accepted April 25th, 2022. link
  2. Vivek Tiwari, “Multidimensional electronic spectroscopy in high-definition—Combining spectral, temporal, and spatial resolutions“, J. Chem. Phys. (2021), 154, 230901. JCP Most Read Perspectives 2021 link.
  3. Sanjoy Patra, Amitav Sahu, and Vivek Tiwari, “Effective Normal Modes Identify Vibrational Motions which Maximally Promote Vibronic Mixing in Excitonically Coupled Aggregates”, J. Chem. Phys. Communication (2021), 154, 111106. Read Research Summary – link
  4. Amitav Sahu, Jo Sony Kurian and Vivek Tiwari, “Vibronic Resonance is Inadequately Described by One-particle Basis Sets”, J. Chem. Phys. (2020), 153, 224114. Feature Article
  5. Abhisek A. Mohapatra, Vivek Tiwari* and Satish A. Patil*, “Energy transfer in ternary blend organic solar cells: recent insights and future directions”, Energy and Environmental Science (2021), 14, 302. Perspective Article (* denotes corresponding authors).
  6. V. Tiwari, Y. A. Matutes, A. T. Gardiner, T. L. C. Jansen, R. J. Cogdell, and J. P. Ogilvie, “Spatially-resolved fluorescence-detected two-dimensional electronic spectroscopy probes varying excitonic structure in photosynthetic bacteria,” Nat. Comm. (2018), 9, 4219. Editors’ Choice
  7. V. Tiwari, W. K. Peters, and D. M. Jonas, “Electronic resonance with anticorrelated pigment vibrations drives photosynthetic energy transfer outside the adiabatic framework,” PNAS (2013), 110, 1203-1208. Science Editors’ Choice, PNAS Cover Mention
  8. V. Tiwari, W. K. Peters, and D. M. Jonas, “Vibronic coherence unveiled,” Nat. Chem. (2014), 6, 173-175. News and Views.