By the same authors

From the same journal

From the same journal

Efficiency of free auxiliary models in describing interacting fermions: From the Kohn-Sham model to the optimal entanglement model

Research output: Contribution to journalArticle

Full text download(s)


Published copy (DOI)


  • Kristian Patrick
  • Marcela Herrera
  • Jake Southall
  • Irene D'Amico
  • Jiannis K. Pachos


Publication details

JournalPhysical Review B
DateAccepted/In press - 2 Aug 2019
DatePublished (current) - 16 Aug 2019
Issue number7
Original languageEnglish


Density functional theory maps an interacting Hamiltonian onto the Kohn-Sham Hamiltonian, an explicitly free model with identical local fermion densities. Using the interaction distance, the minimum distance between the ground state of the interacting system and a generic free-fermion state, we quantify the applicability and limitations of the exact Kohn-Sham model in capturing the various properties of the interacting system. As a by-product, this distance determines the optimal free state that reproduces the entanglement properties of the interacting system as faithfully as possible. The parent Hamiltonian of the optimal free state identifies a system that can determine the expectation value of any observable with controlled accuracy. This optimal entanglement model opens up the possibility of extending the systematic applicability of auxiliary free models into the nonperturbative, strongly correlated regimes.

Bibliographical note

©2019 American Physical Society. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details.

Discover related content

Find related publications, people, projects, datasets and more using interactive charts.

View graph of relations