Scientific Results

Quantum Monte Carlo estimation of complex-time correlations for the study of the ground-state dynamic structure function

Year: 2015

Authors: Rota R., Casulleras J., Mazzanti F., Boronat J.

Autors Affiliation: Univ Trento, Dipartimento Fis, I-38123 Povo, Trento, Italy;‎ Univ Trento, INO CNR BEC Ctr, I-38123 Povo, Trento, Italy; Univ Politecn Cataluna, Dept Fis & Engn Nucl, E-08034 Barcelona, Spain

Abstract: We present a method based on the path integral Monte Carlo formalism for the calculation of ground-state time correlation functions in quantum systems. The key point of the method is the consideration of time as a complex variable whose phase d acts as an adjustable parameter. By using high-order approximations for the quantum propagator, it is possible to obtain Monte Carlo data all the way from purely imaginary time to d values near the limit of real time. As a consequence, it is possible to infer accurately the spectral functions using simple inversion algorithms. We test this approach in the calculation of the dynamic structure function S(q, omega) of two one-dimensional model systems, harmonic and quartic oscillators, for which S(q, omega) can be exactly calculated. We notice a clear improvement in the calculation of the dynamic response with respect to the common approach based on the inverse Laplace transform of the imaginary-time correlation function. (C) 2015 AIP Publishing LLC.


Volume: 142 (11)      Pages from: 114114-1  to: 114114-11

DOI: 10.1063/1.4914995

Citations: 7
data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2021-10-24
References taken from IsiWeb of Knowledge: (subscribers only)
Connecting to view paper tab on IsiWeb: Click here
Connecting to view citations from IsiWeb: Click here

This site uses cookies. If you decide to continue browsing we consider that you accept their use. For more information about cookies and how to delete them please read our Info Policy on cookies use.
Read more