Path Integrals

Path integral calculations scale exponentially with system sizes, making simulations of large systems prohibitively difficult. However, physical systems have certain constraints; interactions, for instance, are generally quite local. Is it possible to use these features to make the cost of path integral simulations indepedent of system size? Explore in depth…

Let’s study spectra for lossy systems! How would the line shapes be affected? How do we exactly quantify the impact of such changes? Our Path Integral Lindblad Dynamics method provides a perfect way of answering these questions. Walk with us while we explore these questions…

How does one incorporate loss and gain mechanisms determined by empirical time-scales in an otherwise numerically exact computation? One way is by combining Lindblad master equations with path integral simulations. Why would one do this? Where are the details? Read more to find out…

Tensors networks are now-a-days being used for simulating the non-equilibrium dynamics of open quantum systems. In this work, we introduce a novel tensor network approach to computing quantum correlation functions for open quantum systems using Feynman-Vernon influence function. Read in full detail…

The different chromophores of the Fenna-Matthews-Olson complex are exposed to different environments. Using path integral simulations and our state-to-state analysis technique, we explore the effect of this inhomogeneity of environment on the exciton transport process. Read more…

Understanding the pathways taken by a quantum particle during a transport process is an enormous challenge. There are broadly two …

The recently introduced multisite tensor network path integral (MS-TNPI) method [Bose and Walters, J. Chem. Phys., 2022, 156, 24101] …

A study of excitonic dynamics and absorption spectra of the LH-II B850 photosynthetic ring using the Multisite Tensor Network Path Integral approach. Read in full detail…

While specific tensor networks like the matrix product state (MPS) have started to prove their utility in simulating non-equilibrium dynamics of quantum systems interacting with a condensed phase, these structures do not manifestly embody the explicit structure of the temporally non-local interactions induced by the condensed phase. Here we introduce a new tensor network which is designed to capture the specific symmetries in the non-Markovian interactions. Read more…

The dimensionality of the Hilbert space required to describe an extended system grows exponentially with the size of the system. We present a method that utilizes tensor networks with Feynman-Vernon influence functional to account for the dynamics of extended systems in presence of local dissipative media. Read in full detail…