Quantum Journal Club: 'Many-body Theory and Discord'

May 19, 2022
11:30am to 1:00pm

IFT Grey Room 1

Specialist level
Speaker: 
Javier Faba
Institution: 
UAM
Location&Place: 

IFT Grey Room 1

Abstract: 
Traditionally, the correlation energy, which is defined as the difference between the mean-field energy and that exact one, has been a measure of the correlations within fermionic systems. However, with the mathematical tools coming from the Quantum Information field, it is possible to obtain a better comprehension of the role of correlations beyond the traditional approaches.
In this talk, I will make use of quantities such as quantum discord and overall entropy in order to analyze the behavior of the correlation energy for solvable albeit rich models. We will see that the two orbital quantum discord can be easily computed for fermionic systems, and it is a good parameter in order to observe quantum phase transitions. Lastly, I will present a variational method in order to compute the quantum discord for fermionic systems and arbitrary orbital partitions, with some examples comparing and analyzing different ground state approximations such has Hartree-Fock, Hartree-Fock with symmetry restoration and Generator Coordinate Method.
Thursday, May 19th, 11:30.