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Schools

Bandstructure meets quantum field theory

July 2, 2018 to July 6, 2018
Location : CECAM-AT

Organisers

  • Karsten Held (Vienna University of Technology, Austria)
  • Georg Kresse (University of Vienna, Austria)
  • Jan Tomczak (Vienna University of Technology, Austria)

Supports

   CECAM

   ERC

FWF SFB ViCoM

Vienna Scientific Cluster (VSC)

Description

A particular challenge of computational materials science is the calculation of materials with strongly correlated electrons, as these call for genuine many body techniques beyond density functional theory (DFT). Dynamical mean field theory (DMFT) and its merger with DFT and Hedin's GW represents a breakthrough in this respect since DMFT includes a major part of electronic correlations: the local ones.


More recently the scientific frontier moved onwards to diagrammatic extensions of DMFT [1] such as the dynamical vertex approximation (DGA) and the dual fermion (DF) approach. These have a local, frequency dependent two-particle vertex as a starting point and construct from this, through Feynman diagrams, non-local correlations in the self-energy and susceptibilities. This diagrammatic route is also much more suited for ab initio material calculations [3,4] than cluster extensions of DMFT.


A Review of Modern Physics [1] is in print and the Summer School covers the whole spectrum from DFT and  GW to DMFT to the Feynman diagrammatic extensions of DMFT. The aim of the Summer School is to educate the next generation of scientists on these approaches through lectures in the morning and hands-
on tutorials in the afternoon.

 

Lectures:
Density functional theory (DFT)
Feynman diagrams and quantum field theory
Many-body perturbation theory (GW)
Dynamical mean-field theory (DMFT)
Continuous-time quantum Monte Carlo (CT-QMC)
Vertex extensions of DMFT
Dual fermion (DF) approach
Dynamical vertex approximation (DGA)

 

Tutorials:
DFT: Wien2K including wien2wannier
GW: VASP
DMFT(CT-QMC): w2dynamics [5]
parquet DGA: victory [2]
ladder DGA and realistic material calculations: AbinitioDGA (ADGA) [4]

Note, the Wien2K and VASP tutorials will provide the starting point for a DFT+DMFT/(qp)GW+DMFT and AbinitioDGA calculation in the 3rd and 5th tutorial. With the Summer School, the program packages w2dynamics, victory and AbinitioDGA will be made available as open source codes.

 

Prerequisites: Solid background in quantum theory, statistical physics, solid state theory. While the lecture series introduces quantum field theory and Feynman diagrams, this is only in a nutshell with little time for the students to reflect. Hence concepts of second quantization, many body Green's functions, self energies should be known. If you are from the bandstructure community, this might mean e.g. that you are familiar with the  formalism around GW. Otherwise it is strongly recommended to read the first chapters of quantum field theory for solid state books such as Zagoskin, Abrikosov, Mahan, Nolting series book 5 etc. before the school.

 

There is no conference fee, but student's travel and accommodation costs are not covered. We have reserved rooms at Kolping Wien Central at a discount rate of 68/40 Euro for single/double room including breakfast. Please indicate if you want us to book this for you in the comments field (see below). Rooms with a window to the quieter road cost 5 Euro more, please also indicate this in the comments section if you prefer that.

 

As social events there is a welcome reception with a glass of sparkling wine at the Kolping Hotel on Sun. evening, a poster session Mo. evening, a museum tour to the Albertina Wed. evening, and a conference dinner to a traditional Wiener Heuriger Thu. evening. Pleas emake up your mind for the latter two since at registration you need to sign for participation of the Heuriger and the Albertina. Please enter your poster title as indicated below.

 

IMPORTANT: The application is through the CECAM "Apply" menu above. This form is however unflexible. Hence please copy/paste the questionnaire below to the "Additional Comments" field at the bottom of the application form with your choices. Please do not forget to list your (most important) publications in the CV field. Shortly after the deadline (March 25, 2018), we will let you know
whether you are admitted to attend our workshop.

 

 

--- to be copied to "Additional Comments" in application form ---

I need a [  ] single room (68 Euro/night), [ ] double  room (40 Euro/night) [with _________]  for the dates [ ] 1.-8. July / [ ] 1.-7. July; [ ] no accommodation.

 

I will [ ] / will not [ ]  present a poster on  my research with title:

__________________________________

 

I will attend [ ] all hands-on courses, [  ] only the lectures,  only the following courses  ___________________________ . Please note that that the number of computers is a limit for the number of participants.

 

 

My two main areas of research/research interests are:

1)_____________________________

2)_____________________________

 

Additional comments:

--- end to be copied to "Additional Comments" in application form ---

References

[1] Diagrammatic routes to non-local correlations beyond dynamical mean field theory.
G. Rohringer, H. Hafermann, A. Toschi, A. A. Katanin, A. E. Antipov, M. I. Katsnelson, A. I. Lichtenstein, A. N. Rubtsov, and K. Held.
Rev. Mod. Phys. 90, 025003 (2018) arXiv:1705.00024

[2] The victory project v1.0: an efficient parquet equations solver.
G. Li, A. Kauch, P. Pudleiner, and K. Held.
Preprint: arXiv:1708.07457 (2017)

[3] Ab initio dynamical vertex approximation.
A. Galler, P. Thunström, P. Gunacker, J. M. Tomczak, and K. Held.
Phys Rev. B 95, 115107 (2017)
Preprint: arXiv:1610.02998 (2016)

[4] The AbinitioDGA Project v1.0: Non-local correlations beyond and susceptibilities within dynamical mean-field theory.
A. Galler, P. Thunström, J. Kaufmann, M. Pickem, J. M. Tomczak, and K. Held.
Preprint: arXiv:1710.06651 (2017)

[5] Merging GW with DMFT and non-local correlations beyond.
J. M. Tomczak, P. Liu, A. Toschi, G. Kresse, K. Held.
Eur. Phys. J. Special Topics 226, 2565–2590 (2017)
Preprint: arXiv:1703.08446

[5] w2dynamics: Local one- and two-particle quantities from dynamical mean field theory
M. Wallerberger, A. Hausoel, P. Gunacker, A. Kowalski, N. Parragh, F. Goth, K. Held, G. Sangiovanni,
Preprint: arXiv:1801.10209