The center for Theoretical Physics (CPHT) at Ecole Polytechnique gathers research scientists working in diverse domains of fundamental and applied Physics. The overall coherence is assured by the corpus of common, transposable, mathematical and numerical methods.
CPHT is a joint research unit of CNRS and Ecole Polytechnique, and has a partnership with the Collège de France. His director is Jean-René Chazottes, Senior Researcher at CNRS.
CPHT is on the campus of Ecole Polytechnique, buildings 5 and 6. The reception offices are located in building 6 , offices 06.1046 and 06.1045.

Postal Address :
Ecole Polytechnique 
91128 Palaiseau cedex 

Secretary phone number : 01 69 33 42 01 (from abroad: +33 169 334 201)

Write an email to someone at CPHT :  :



Since 2019 the Department of Physics and Astronomy at Heidelberg University has been awarding two thesis prizes per year, sponsored by the Wilhelm and Else Heraeus Foundation.

Sabine Harribey is one of the 2022 laureates for her work "Renormalization in tensor field theory and the melonic fixed point," carried out jointly at the École polytechnique (CPHT) and at Heidelberg, under the supervision of D. Benedetti and R. Gurau.

Site officiel


The 7th CPHT Young Researchers Seminar will be held on January 27, 2023 at 3:00 p.m. in the Louis Michel Conference Room with two presentations given by :

Frederick del Pozo (CPHT, CNRS, École Polytechnique) : Fractional topology and Majoranas in 1D Superconductors

Dawei Shen (LJLL, CNRS, Sorbonne Université) : Feynman propagator on asymptotically Minkowski spacetimes

The seminar will be followed by a high tea.



PhD Student

Resarch activities at CPHT: Condensed Matter

Research interests: Topology, Quantum Information, Condensed Matter, Theoretical Physics, Quantum Physics, Many-Body physics

Thesis:  "Topological Materials, Semimetals and Quantum Information"

AdvisorKaryn Le Hur


The objective of this thesis is to study the topological and physical properties of a new class of topological semimetals recently discovered in the group. These semimetals exhibit fractional topological properties due to the particular geometry of their band structure, involving quantum entanglement properties in the Brillouin zone. The first part of this thesis will consist in studying these quantum properties in order to identify the nature of the protection of this topological phase of matter. During this first part of the thesis, we will also be interested in identifying possible experimental protocols, including light-matter interactions protocols, with aim of experimental demonstration of these fractional topological phases by characterizing the properties of thermodynamic and transport observables within these topological phases. Particular attention will be paid to the effects of interactions on the topology of the system. Eventually, the goal is to develop new theoretical and numerical tools for the systematic study and characterization of these fractional topological phases of matter for technological purposes with links to entanglement and quantum information.



Address CPHT, Ecole Polytechnique, 91128 Palaiseau cedex, France
Phone number 01 69 33 42 76
Office Aile zéro, Office 1018




The publication of Alexander Friedmann's seminal papers in 1922 marked the birth of modern cosmology. In order to celebrate its centenary, the Friedmann Endowment will fund various scientific actions over the next few years, covering the wide range of themes associated with cosmology, at École Polytechnique and partner institutions, in collaboration with the Foundation of Ecole Polytechnique. The Friedmann Colloquium will be a flag activity, organized by the Physics Department and aimed at a general audience of scientists and science students.

For its first edition of the Friedmann Colloquium, Dr. Frank Eisenhauer from the Max Planck Institute for Extraterrestrial Physics, Munich (Garching) will speak about : THE GALACTIC CENTER BLACK HOLE, THE EFFECTS OF GENERAL RELATIVITY, AND HOW TO OBSERVE THEM

Monday, December 5, 2022 at 6:00 pm in Becquerel Lecture Hall of Ecole polytechnique

Abstract found at :

The program and the videos of the conferences of the Physics Department are available on the Department website:

About the Alexander Friedmann Endowment
In 1922 Alexander Friedmann (1888-1925) published a seminal paper, which triggered the advent of modern cosmology. In order to celebrate its centenary, the Alexander Friedmann Endowment supports various scientific activities, covering the wide range of subjects associated with cosmology, at Ecole Polytechnique and its partner institutions. Among these activities, the Friedmann Colloquium is a general seminar addressing an audience of scientists and science students.
Scientific committee : Silke Biermann (CPHT), Jean-René Chazottes (CPHT), Mathieu de Naurois (LLR), Marios Petropoulos (CPHT), Sébastien Renaux-Petel (IAP), Yves Sirois (LLR).



The students conference is organized this year on Friday, November 25, Becquerel amphitheatre.

speakers and titles

9h15 - 10h45

1-Jean-Gabriel Thiriet (Stability analysis of ablation flows in inertial-confinement fusion: receptivity)
2-Adrien Loty (Unitarity constraints on maximally supersymmetric string theories)
3-Theophile Truchis (Metastability and state clustering in evolutionary games)
4-Zhaoxuan Zhu (Thermodynamic phase diagram of two-dimensional bosons in a quasicrystal potential)
5-Matthieu Vilatte (A dive into the Carrollian world)
6-Majdouline Borji (Perturbative renormalization of boundary field theory)
7-Victor Franken (Entanglement builds bridges (in quantum gravity)

11h15 - 12h30

8-Ephraim  Bernhardt (Topology of spin-1/2 systems and relations to a « quantum dynamo)
9-Dylan Bansard-Tresse (Extreme value laws and hitting times for dynamical systems)
10-David Rivera Betancour (Carrollian perspective of fluids and holography)
11-Frederick del Pozo (Fractional topology in one-dimensional interacting superconductors)
12-Pauline Besserve (Selected aspects of quantum algorithmics for the quantum many-body problem in the noisy era)
13-Mathieu Beauvillain (Non-linear edge dynamics for quantum-hall droplets)

14h45 - 16h15

14-Mohamed Rekhis (Toroidally-induced Alfven eigenmode (TAE) destabalization by energetic particles in tokamak plasmas)
15-Erik Linner (Multi-channel fluctuating field approach to competing instabilities in interacting electronic systems)
16-Sariah Al Saati (Topological Nodal Ring Semimetal in Graphene)
17-Gabriele Casagrande (Minimal supergravity models for inflation)
18-Anustrup Mukerjee (Search for novel transition metal chalcogenides for thermoelectric applications)
19-Liam Rampon (Exploring strongly correlated condensed matter using numerical methods)
20-Pierre Wang (Triviality of phi-4 theory in the mean field approximation)

Tea Time




James Boust soutiendra publiquement ses travaux de thèse le 18 novembre 2022 au CPHT dans la salle de conférence Louis Michel.

Titre de la thèse : Propriétés magnétiques et optiques de composés de terres rares corrélés à partir des premiers principes 

Membres du Jury :
Alexander Lichtenstein (Universität Hamburg)
Markus Aichhorn (Graz University of Technology)
Silke Biermann (Ecole polytechnique)
Nora Dempsey (Institut Néel CNRS)
Olle Eriksson (Uppsala University)
Cesare Franchini (Universität Wien)

Abstract: In so-called "strongly correlated" materials, the strong Coulomb interaction which correlates the movement of electrons at the atomic scale can give rise to outstanding properties at the macroscopic scale. The materials studied in this thesis contain rare-earth elements (like neodymium) which usually exhibit these strong correlation effects. Due to their remarkable properties, rare-earth compounds have numerous technological applications; they are for instance used as high-performance magnets in electric motors. The demand for rare earths is therefore increasing; on the other hand, mining them is difficult, expensive and polluting. Hence, optimizing the properties and composition of rare-earth-based materials can be of great technological, economical and environmental interest. From the point of view of theoretical physics, describing these materials constitutes a real challenge, precisely due to their strongly correlated nature. In this thesis, we develop theoretical approaches to study the magnetic and optical properties of rare-earth compounds, notably the industrially relevant neodymium magnet. These theoretical methods are said to be from "first principles" as they are based on the fundamental laws governing the physics at the atomic level.