A linear response framework for simulating bosonic and fermionic correlation functions illustrated on quantum computers
Abstract
Response functions are a fundamental aspect of physics; they represent the link between experimental observations and the underlying quantum many-body state. However, this link is often under-appreciated, as the Lehmann formalism for obtaining response functions in linear response has no direct link to experiment. Within the context of quantum computing, and by using a linear response framework, we restore this link by making the experiment an inextricable part of the quantum simulation. This method can be frequency- and momentum-selective, avoids limitations on operators that can be directly measured, and is ancilla-free. As prototypical examples of response functions, we demonstrate that both bosonic and fermionic Green's functions can be obtained, and apply these ideas to the study of a charge-density-wave material on ibm_auckland. The linear response method provides a robust framework for using quantum computers to study systems in physics and chemistry. It also provides new paradigms for computing response functions on classical computers.
Cite
@article{arxiv.2302.10219,
title = {A linear response framework for simulating bosonic and fermionic correlation functions illustrated on quantum computers},
author = {Efekan Kökcü and Heba A. Labib and J. K. Freericks and Alexander F. Kemper},
journal= {arXiv preprint arXiv:2302.10219},
year = {2023}
}