Pres splds 2012
-
Upload
gaelmonney -
Category
Business
-
view
239 -
download
0
Transcript of Pres splds 2012
![Page 1: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/1.jpg)
Electron – holeinstabilities in TiSe2
Gaël MonneyUniversity of Fribourg, Switzerland
![Page 2: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/2.jpg)
Our group & collaborators
Electron spectroscopy group in Fribourg• Clément Didiot, Zuzana Vydrova,
Nicolas Mariotti (Gunnar Garnier, Eike Schwier)
• Philipp Aebi Collaborations• Hans Beck, Univ. of Neuchâtel• Claude Monney, PSI, Switzerland• H. Berger, EPFL
1
![Page 3: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/3.jpg)
Part 1 :
The context
![Page 4: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/4.jpg)
Charge density waves (CDW) Peierls transitions (electron signature)
2
![Page 5: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/5.jpg)
Charge density waves (CDW) Kohn anomaly (phonon signature)
3
![Page 6: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/6.jpg)
CDW : driving forces Fermi Surface Nesting
Jahn-Teller effect
Excitons
4
![Page 7: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/7.jpg)
TiSe2 properties
Reciprocal space
Real space
TiSe
Di S
alvo
et a
l., P
RB,
1976
5
![Page 8: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/8.jpg)
Part 2 :
Experiments
![Page 9: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/9.jpg)
Electronic signatures (by ARPES)
6
![Page 10: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/10.jpg)
Other measurements 7
![Page 11: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/11.jpg)
Part 3 :
The models
![Page 12: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/12.jpg)
Exciton BCS model ( )
Hamiltonian
Green’s functions
Anomalous Green’s functions
Order parameter
8
![Page 13: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/13.jpg)
Exciton BCS model ( )
9
Previous model : Hervé Cercellier et al., PRL, 2007
![Page 14: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/14.jpg)
Electron – hole fluctuations ( ) The model
Definitions
Electron-hole susceptibility
Bethe-Salpeter equation
10
![Page 15: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/15.jpg)
Electron – hole fluctuations The physics
11
![Page 16: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/16.jpg)
Part 4 :
The results
![Page 17: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/17.jpg)
Crossings vs. nesting 12
![Page 18: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/18.jpg)
Electron renormalization Comparison
13
![Page 19: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/19.jpg)
Phonon renormalization 14
![Page 20: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/20.jpg)
Part 5 :
Outlook
![Page 21: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/21.jpg)
Chirality 15
![Page 22: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/22.jpg)
Thanks
![Page 23: Pres splds 2012](https://reader035.fdocuments.in/reader035/viewer/2022070519/58ef6d861a28ab567d8b464f/html5/thumbnails/23.jpg)
Part I : CDWs
Part 2 : Experiments
Part 3 : Models
Part 4 : Results