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 :
CPHT 
Ecole Polytechnique 
91128 Palaiseau cedex 
France

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

Write an email to someone at CPHT :  : firstname.lastname@polytechnique.edu

 

Workshop on Electronic and Thermal Transport in Frontier Materials, October 2-3

We are organizing a workshop on Electronic and Thermal Transport in Frontier Materials on October 2-3.
The talks will be held at Salle Louis Michel of CPHT on Oct 2 afternoon and Oct 3 morning.
The goal of the workshop is to bring together and exchange ideas between scientists working on thermoelectricity and transport phenomena in novel and interesting materials.

Workshop Schedule
Thursday, Oct 2 
14h00 - 14h45 Jonathan Alaria, From Bonds to Bands: Controlling Transport through Structural Motifs
14h45 - 15h30 Gael Grissonnanche, How can thermoelectric measurements probe quantum criticality?
15h30 - 15h45 Break
15h45 - 16h30 Andrje Pustogow, Flat Bands and Geometrical Frustration Boost Metallic Thermoelectrics
16h30 - 17h15 Jennifer Coulter, Advanced methods for first-principles Boltzmann transport predictions
17h15 - 17h35 Laura Agnarelli, Crystal Structure and Transport Properties in Ni7-xSnS2 and Ni10-xSn2S2
17h35 - 17h50 Break
17h50 - 18h35 Solveig Aamlid, Thermal properties of high entropy oxides
18h35 - 18h55 Anustup Mukherjee, Thermoelectric transport properties of hole-doped FeS2 and a lattice thermal conductivity comparison with RuS2

Friday, Oct 3
9h00 - 9h45 Silke Paschen, Weyl-Kondo semimetals
9h45 - 10h30 Krzysztof Wojciechowski, Composite Thermoelectric Materials with Attuned Electronic Structure and Mismatched Phonon Structure (AES-MPS)
10h30 - 10h45 Break
10h45 - 11h30 Jelena Sjakste, Coupled dynamics and transport of hot carriers and phonons in photoexcited semiconductors: theoretical approaches based on real-time propagation of carrier distributions
11h30 - 12h15 Jan-Willem Bos, Thermoelectric transport in half-Heusler and metal phosphide materials
12h15 - 13h00 Antoine Maignan, Thermopower, anomalous effects and magnetism in selected metallic oxides and metal-rich sulfides

Organisers
Alaska Subedi (CPHT)
Ramzy Daou (CRISMAT, Caen)
Laura Agnarelli (CRISMAT, Caen)
Sylvie Hebert (CRISMAT, Caen)

 

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séminaire conjoint LSI+CPHT+PMC = M4S

Séminaire conjoint LSI+CPHT+PMC = M4S

vendredi 19 septembre à 10h

nouvelle salle de séminaire du PMC (anciennement salle Jean Mandel, au RDC de l'aile 5, près de l'aile 3).

Ioan Pop
(Karlsruhe Institute of Technology)

"Superconducting qubits and amplifiers resilient to tesla-scale magnetic fields"

Superconducting qubits with quantum non-demolition readout and active feedback can act as information engines to probe and control microscopic degrees of freedom, both engineered and environmental. However, the magnetic field bias poses a significant challenge for the operation of conventional qubits. We demonstrate a fluxonium qubit with a granular aluminum nanojunction (gralmonium) that maintains spectral stability and coherence above 1 T [arxiv.org/abs/2501.03661]. This robust performance enables exploration of spin environment dynamics and supports hybrid quantum architectures integrating superconducting qubits with spin systems.

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SUCCESS-2025, Les Houches 15-26 september 2025

 

Doctoral Training: SUCCESS-2025 - School on Ultraviolet and X-Ray Spectroscopies of Correlated and Topological Electron Systems

15 - 26 september 2025

Les Houches

Strong electron correlations and topology lie at the heart of quantum materials and their exotic states of matter. These are best understood by studying their electronic structure. This school, addressed to PhD students and young researchers, will introduce the recent experimental and theoretical developments in UV and X-ray spectroscopies, from their basic principles to their applications in the study of correlated materials.

The organizers:
Andrés F. Santander-Syro – Université Paris-Saclay (Orsay, France)
Silke Biermann – Institut Polytechnique de Paris (Palaiseau, France)
Patrick Le Fèvre – Université de Rennes (Rennes, France)
Ralph Claessen – Universität Würzburg (Germany)

More information can be found on the session's website.

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CPHT Young Researcher Seminar

 

The CPHT Young Researchers Seminar will be held on Monday the 30th of June at 3:00 PM  in room Louis Michel :

Valentine Maris from ENS de Lyon Introduction to noncommutative geometry and deformed Minkowski space-time :
Noncommutative geometry provides a representation of space-time in terms of associative algebras of operators. The final goal is to end up with a "quantum space-time" which should encode quantum gravity effects at an effective level. Recently, construction of such quantum space-times has been investigated and led to deformations of the usual Minkowski space-time.

Thomas Pochart QFT in AdS and its flat-space limit :
The Anti-de Sitter space is a fundamental concept in physics, arising naturally in GR and playing a key role in holography. We will discuss recent advances in quantum field theory for AdS spaces, and in particular its large radius limit, in which it is expected that we efficiently recover flat-space quantities.

The seminar will be followed by a high tea.

English

Seminar announcement

Monday 30th June at 11:00am – Seminar Room Louis Michel at CPHT, Ecole Polytechnique
 
Title: Topological superconductivity and charge order in Sn/Si(111)
 
Stephan Rachel, University of Melbourne Australia
 
Abstract:
In this talk, I will discuss competing many-body states on the triangular lattice. Motivated by the recently discovered superconductivity in boron-doped Sn/Si(111) with a Tc as high as 10K [1], I will focus on unconventional superconductivity of correlated electrons on the triangular lattice. I will further demonstrate the significance of Rashba spin-orbit couling for materials such as Sn/Si(111) and show that the superconducting phase possesses a surprisingly rich Chern-number landscape [2]. I will discuss the implications of our findings for Sn/Si(111), compare observables and also emphasize the significance of related compounds such as Pb/Si(111) and Sn/SiC(0001) [3].
 
[1] F. Ming, X. Wu, C. Chen, K. D. Wang, P. Mai, T. A. Maier, J. Strockoz, J. W. F. Venderbos, C. Gonzalez, J. Ortega, S. Johnston, and H. H. Weitering, Nat. Phys. 19, 500 (2023).
[2] M. Bunney, J. Beyer, R. Thomale, C. Honerkamp, S. Rachel, Phys. Rev. B Letters 110, L161103 (2024).
[3] L. Marchetti, M. Bunney, D. Di Sante, S. Rachel, Phys. Rev. B 111, 125115 (2024).
 
Join Zoom Meeting
Meeting ID: 937 3477 1384
Passcode: 313476
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Seminar announcement

Friday 27th June at 14:00pm – Seminar Room Louis Michel at CPHT, Ecole Polytechnique
 
Topological devil's step in a constrained kagome Ising antiferromagnet
 
Jeanne Colbois, CNRS and Institut Louis Neel, Grenoble
 
Despite their apparent simplicity, classical Ising models can give rise to exotic ground state phases in the presence of frustration (e.g., when antiferromagnetic pair interactions cannot be simultaneously minimized) [1]. The finite-temperature physics induced by such  macroscopically degenerate ground states can prove extremely rich, but, except at fine-tuned point, studying them with numerical or analytical methods can prove difficult. 
 
I will briefly describe how tensor network methods -- well known for their success in  the study of quantum spin systems -- can also help solve such classical statistical mechanics problems on a lattice [2,3]. As a case in point, I will discuss a surprising staircase behavior observed in the constrained limit of a farther-neighbor kagome Ising antiferromagnet. After recalling some key notions, I will argue that, unlike in standard Devil's staircases, the driving mechanism here is Kastelyn-like and leads to a staircase of topological origin [4].
 
[1] C. Lacroix, P. Mendels, and F. Mila, Introduction to Frustrated Magnetism: Materials, Experiments, Theory (2011)
[2] B. Vanhecke, J. Colbois et al, Solving Frustrated Ising models using tensor networks, Phys. Rev. Res, (2021)
[3] J. Colbois, B. Vanhecke et al, Partial lifting of degeneracy in the J1-J2-J3 Ising antiferromagnet on the kagome lattice, Phys. Rev. B (2022)
[4] A. Rufino, S. Nyckees, J. Colbois, and F. Mila, Topological devil's staircase in a constrained kagome Ising antiferromagnet, arXiv:2505.05899
 
 
Join Zoom Meeting
Meeting ID: 939 9582 7714
Passcode: 697603
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CPHT Young Researcher Seminar

 

The CPHT Young Researchers Seminar will be held on Friday the 13th of June at 2:00 PM  in room Louis Michel :

Fanny Eustachon  CFT in higher dimensions for dummies

Francesco Cassol Interplay of Spin-orbit coupling, Coulomb interaction and magnetism in iridate materials: the example of Ba2IrO4 and Sr2IrO4

The seminar will be followed by a high tea.

English

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