1. Teoria quantistica:
Polaritone

2. Teoria quantistica: Polaritone

3. Sommario eccitone Stato isolato nel gap Transizione tunabile
Spin intero
Picco di assorbimento ben separato dal continuo e-h
Stato isolato nel gap
Transizione tunabile
Statistica bosonica
Moto libero nel piano (k//)

4. Sommario MC Stato isolato nel gap Transizione tunabile
Statistica bosonica
Moto libero nel piano (k//)

5. Sommario interazione classica
bare photon
bare exciton
bare exciton
bare photon

6. Photon state in second quantization and k space
Electromagnetic Vacuum

7. Funzione inviluppo eccitone
Eccitone 1s (prima quantizzazione) +e -e
Funzione inviluppo eccitone

8. Elettroni e lacune in seconda quantizzazione
Onda CB
Onda VB
Linguaggio elettroni

9. Linguaggio elettroni

14. Half-photon, half-exciton

15. Anticrossing k//=0

16. Accordo in frequenza Controllo deterministico del tuning a posteriori
Cavità con gradiente

17. GaAs

18. Effetti quantistici
BEC polaritoni

19. Anticrossing k//=0

20. Lower polariton states

21. Bose-Einstein condensation (BEC) of an ideal Bose gas1
The Bose-Einstein distribution function:
In a d-dimensional system with a parabolic dispersion around k=0:
In a 3D (d=3) system with a parabolic dispersion around k=0:
1 S.N. Bose, Z. Phys. 26, 178 (1924), A. Einstein, Sitzber. Kgl. Preuss. Akad. Wiss (1924).

23. Scattering
risonante

24. Fononi distruggono strong coupling

25. Exciton scattering distrugge
strong coupling

26. Esistenza polaritone Broadening distrugge Strong coupling
Coupling regimes
Broadening distrugge
Strong coupling

27. Phase diagram of exciton-polaritons
Weak coupling
Weak coupling
Strong coupling
Solid lines show the critical concentration Nc versus temperature of the polariton KT phase transition. Dotted and dashed lines show the critical concentration Nc for quasi condensation in 100 µm and 1 meter lateral size systems, respectively.

28. Phase diagrams of exciton-polaritons in different materials
Solid lines show the critical concentration Nc versus temperature of the polariton KT phase transition. Dotted and dashed lines show the critical concentration Nc for quasi condensation in 100 µm and 1 meter lateral size systems, respectively.

29. Trappola in k space per polaritoni

30. CdTe T=5K

31. GaN
Polaritons
at T=300K

32. BEC in 300K

33. Polariton laser

34. Laser history...
1917 Einstein derived the Plank formula, spontaneous + stimulated emission
1950 W. Lamb: idea of light amplification
1950 A. Kastler, optical pumping
1953 Weber, Twones, Basov, Prokhorov, maser
1959 T.H.Maiman, laser on rubis
1960s gaz lasers
1969 first semiconductor lasers (pn-junction)
1972 Zh. Alferov, laser on heterostructures
1990s lasers on semiconductor nanostructures, VCSELs
1996, Imamoglou, idea of polariton lasing
2007, RT polariton laser

35. To make a polariton laser one should have a microcavity in the strong-coupling regime
Coherent spontaneous
emission from
polariton BEC
Optically or electronically excited exciton-polaritons relax towards the ground state and Bose-condense there. Their relaxation is stimulated by final state population. The condensate emits spontaneously a coherent light

36. Escape of polaritons from cavity