We review an ab-initio method for calculating the dynamical structure function of an interacting many-body quantum system. The method consists in coupling a generalized integral transform approach with imaginary time Quantum Monte Carlo calculations. The strength of the method has been tested on the excitation spectrum of bulk atomic 4He. The peculiar form of the kernel as a representation of the delta-function has allowed to minimize the ill-posedness of the integral transform inversion. In fact it has been possible to obtain, at a considerable degree of reliability, both position and width of the collective excitations in the maxon-roton region, as well as the second collective peak. What we stress here is the ability of such a 4-function-like kernel, for which one can control position and width, to maintain in the transformed space the characteristics of the collective structures. The application to the coherent and incoherent density excitation spectrum of liquid 4He is discussed.
Scheda prodotto non validato
I dati visualizzati non sono stati ancora sottoposti a validazione formale da parte dello Staff di IRIS, ma sono stati ugualmente trasmessi al Sito Docente Cineca (Loginmiur).
Titolo: | Use of the Sumudu transform to extract response functions from Quantum Monte Carlo calculations |
Autori: | Pederiva, Francesco; Roggero, Alessandro; Orlandini, Giuseppina |
Autori Unitn: | |
Titolo del periodico: | JOURNAL OF PHYSICS. CONFERENCE SERIES |
Anno di pubblicazione: | 2014 |
Numero e parte del fascicolo: | 1 |
Codice identificativo Scopus: | 2-s2.0-84904642097 |
Codice identificativo ISI: | WOS:000340240100011 |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1088/1742-6596/527/1/012011 |
Handle: | http://hdl.handle.net/11572/111757 |
Appare nelle tipologie: | 03.1 Articolo su rivista (Journal article) |
File in questo prodotto:
File | Descrizione | Tipologia | Licenza | |
---|---|---|---|---|
sumudu1.pdf | Versione editoriale (Publisher’s layout) | Tutti i diritti riservati (All rights reserved) | Administrator |