What is it about?
Non-adiabatic nuclear dynamics is a long standing quantum many-body problem that solves the equations for quantum dynamics that is associated with many coupled electronic and vibrational quantum states. The main breakthrough of this work is that it heuristically reduces the cost of quantum simulation for the non-adiabatic dynamics problem from exponential scaling over the number of degrees of freedom (dof) to low order polynomial. The key idea to achieve this is the use of second quantization techniques which is borrowed from the quantum field theory. As a result, we form a compact representation of the time-dependent wavefunction. In this way, the number of independent parameters scales classically (polynomial) over the dof of the system in this compact representation of the time-dependent wavefunction.
Featured Image
Photo by Sangharsh Lohakare on Unsplash
Why is it important?
Though this research is purely theoretical, the computational method developed in this work can be applied to understand many complicated processes in physics and chemistry such as high temperature superconductivity and intersystem crossing of singlet fission.
Perspectives
It is widely believed that using quantum computer to do quantum chemistry or more general quantum simulation is one of the most promising applications of quantum computers. However, this work might make people rethink what is the true “quantum advantage”? Conventional wisdom believed that quantum simulations have an exponential scaling of the size of the systems on a classical computer. However, the classical algorithm can be optimized that provide a heuristic solution of the quantum many-body problem efficiently. The algorithm proposed in this work is an example of one of those “smart” classical algorithms.
Songhao Bao
University of Waterloo
Read the Original
This page is a summary of: Time dependent vibrational electronic coupled cluster (VECC) theory for non-adiabatic nuclear dynamics, The Journal of Chemical Physics, March 2024, American Institute of Physics,
DOI: 10.1063/5.0190034.
You can read the full text:
Contributors
The following have contributed to this page
