HOME > Activities > Seminars & Lectures
Seminars & Lectures
* TITLE Multipoint correlation functions: spectral representation and numerical evaluation
Name Affiliation E-mail
Seung-Sup Lee Ludwig Maximilian University of Munich s.lee(at)lmu.de
* HOST(Applicant)
Name Affiliation E-mail
Imtak Jeon APCTP
* DATE / TIME 2021-03-29, 16:00
* LINK https://zoom.us/meeting/register/tJ0tc-iprzgsG9TAsZFy8Wf45_ny9cOhB5QC
Four-point correlation functions on the real-frequency axis describe experimentally relevant properties, such as nonlocal susceptibilities, transport, and inelastic photon scattering, of the systems of interacting quantum particles. However, the non-perturbative computation of real-frequency multipoint functions has been intractable. In this talk, I will summarize our recently developed method for non-perturbatively computing multipoint functions and its applications [1, 2]. We have derived generalized spectral representations for multipoint functions that apply in all of the commonly used many-body frameworks [1]: the imaginary-frequency Matsubara and the real-frequency zero-temperature and Keldysh formalisms. We have developed a numerical renormalization group (NRG) method for evaluating the spectral representations for local multipoint functions, which can treat temperatures and frequencies---imaginary or real---of all magnitudes, from large to arbitrarily small ones [2]. I will present the numerical results of four-point vertex functions and resonant inelastic x-ray scattering (RIXS) spectra of quantum impurity systems.

[1] F. B. Kugler*, S.-S. B. Lee*, and J. von Delft, arXiv:2101.00707.
*: These authors contributed equally to this work.
[2] S.-S. B. Lee, F. B. Kugler, and J. von Delft, arXiv:2101.00708.
How to get to APCTP
Scientific Activities Calendar
Scientific programs
TEL : +82-54-279-8661~5
FAX : +82-54-279-8679
E-mail : apctp(@)apctp.org
RSS Feeds
Hogil Kim Memorial Building #501 POSTECH,
77 Cheongam-ro, Nam-gu, Pohang-si, Gyeongsangbuk-do, 37673, Korea