ICTP2020

Plan for the ICTP 2020 school tutorials

Setting up the Yambo Quantum Machine

The tutorials will be run on a dedicated Quantum Machine. This is run by installing it as Virtual Machine with the VirtualBox program.

• VirtualBox is installed on your PC. To find it open a terminal and

>which virtualbox
/usr/bin/virtualbox

• The Yambo Quantum Machine image (.ova file) is already in the /scratch

>cd /scratch
>/scratch$ ls
(...) YAMBO_Quantum_Mobile.ova

Now follow exactly the instructions to

• Install the Yambo Quantum Machine
• Start the Yambo Quantum Machine
• Update and install the Tutorials

Monday 27 Jan HANDS-ON 1

14:40 - 17:00 From the DFT ground state to the complete setup of a Many Body calculation using Yambo Davide Sangalli (CNR-ISM, Italy), Pedro Melo (University of Liege, Belgium)

• First steps: walk through from DFT to RPA (standalone)

Tuesday 28 Jan HANDS-ON 2

14:00 - 18:00 A complete tour through GW simulation in a complex material (from the blackboard to numerical computation: convergence, algorithms, parallel usage) Daniele Varsano (CNR-NANO, Italy), Andrea Ferretti (CNR-NANO, Italy)

• How to obtain the quasi-particle band structure of a bulk material: h-BN

16:30 - 18:00 A complete tour through GW simulation in a complex material (from the blackboard to the computer settings: convergence, algorithms, parallel usage) (continued) Daniele Varsano (CNR-NANO, Italy), Andrea Ferretti (CNR-NANO, Italy)

• Parallel GW: strategies for running Yambo in parallel
• GW convergence: use Yambo in parallel to converge a GW calculation for a layer of hBN (hBN-2D)

Link to old CECAM specific cases: GW_parallel_strategies_CECAM and Pushing_convergence_in_parallel_CECAM

Wednesday 29 Jan HANDS-ON 3

14:00 - 16:00 A guided tour through calculations of spectroscopic properties using the BSE approach Daniele Varsano (CNR-NANO, Italy), Maurizia Palummo (University of Rome Tor Vergata, Italy)

• Calculating optical spectra including excitonic effects: a step-by-step guide
• Obtaining a converged optical spectrum

16:30 - 18:00 Many-body effects in 2D materials: convergences, exciton characterizations Maurizia Palummo (University of Rome Tor Vergata, Italy), Attaccalite Claudio (CNRS, CINAM, Aix-Marseille Univ., France)

• Many-body effects in low-dimensional systems: numerical issues and remedies
• Analysis of excitonic spectra in a 2D material

Thursday 30 Jan HANDS-ON 4

14:00 - 15:00 Real-time approach and Calculation of linear response functions and optical properties Claudio Attaccalite (CNRS, CINAM, Aix-Marseille Univ., France), Davide Sangalli (CNR-ISM, Italy)

• Linear response from real time simulations

15:30 - 18:00 Real time approach and Calculation of non linear properties (second harmonic generation) Claudio Attaccalite (CNRS, CINAM, Aix-Marseille Univ., France), Davide Sangalli (CNR-ISM, Italy)

• Real time approach to non-linear response
• Correlation effects in the non-linear response

Friday 31 Jan HANDS-ON 5

09:00 - 10:30 Python scripting tools for accelerated GW convergence Fulvio Paleari (CNR-ISM, Italy), Alejandro Molina-Sanchez (IINL, Portugal)

• First steps in Yambopy
• GW tutorial. Convergence and approximations (BN)

10:30 - 11:30 Python scripting tools for BSE convergence and analysis Fulvio Paleari (CNR-ISM, Italy), Pedro Melo

• Bethe-Salpeter equation tutorial. Optical absorption (BN)

Lectures

Monday, 27 January: Excited-state properties in Many-Body Perturbation Theory (MBPT)

• Description and goals of the school: From theoretical concepts to real computation of the excited states properties of complex materials by first principle
• Introduction to Many body perturbation theory
• Correlation and Diagrams
• The GW method: an Heuristic approach

• Introduction to Material Science

• Experimental lecture on photoemission spectroscopy
• Beyond the independent particle scheme: The linear response theory

Tuesday, 28 January: Electronic properties: from DFT to the quasi-particle equation and the GW method

• The Quasi Particle concept and the GW method
• The GW scheme: common approximations and practical implementations
• High throughput calculations: from DFT to GW

Wednesday, 29 January. Optical properties and the electron-hole interaction

• Derivation of the Bethe-Salpeter Equation and main physical concepts
• Real_time_approach_to_the_BSE.pdf The Bethe-Salpeter Equation: common approximations and practical implementations
• Many Body effects in low dimensional materials

Thursday, 30 January. Real time approaches for linear and non-linear optical propertiers

• Real-time Many-Body simulation: propagating the density matrix
• Real-time Many-Body and Berry phase for non-linear optics