QuDPy: A Python-Based Tool For Computing Ultrafast Non-linear Optical Responses

TL;DR

QuDPy is a Python tool that enables accurate quantum dynamical simulations of nonlinear optical responses, facilitating interpretation of multi-dimensional spectra in chemistry, biology, and physics.

Contribution

This paper introduces QuDPy, a new Python-based platform that allows flexible specification and computation of high-order optical responses using quantum dynamics simulations.

Findings

Supports simulation of any n-th-order optical response

Allows straightforward input of response pathways via Feynman diagrams

Demonstrates utility through example calculations

Abstract

Nonlinear Optical Spectroscopy is a well-developed field with theoretical and experimental advances that have aided multiple fields including chemistry, biology and physics. However, accurate quantum dynamical simulations based on model Hamiltonians are need to interpret the corresponding multi-dimensional spectral signals properly. In this article, we present the initial release of our code, QuDPy (quantum dynamics in python) which addresses the need for a robust numerical platform for performing quantum dynamics simulations based on model systems, including open quantum systems. An important feature of our approach is that one can specify various high-order optical response pathways in the form of double-sided Feynman diagrams via a straightforward input syntax that specifies the time-ordering of ket-sided or bra-sided optical interactions acting upon the time-evolving density matrix of the system. We use the quantum dynamics capabilities of QuTip for simulating the spectral response of complex systems to compute essentially any n-th-order optical response of the model system. We provide a series of example calculations to illustrate the utility of our approach.