1. Time-Resolved Photoemission Spectroscopy
Supansa Musikajaroen D

2. Outline Introduction Time-resolved photoemission measurement
Experimental set up
- Light source
- Ultrahigh Vacuum (UHV) Analysis Chamber
- Time Of Flight (TOF) Spectrometer

3. Introduction Time-resolved photoemission measurement :
can offer the real-time study of the dynamics of the electronic state in condensed matter
used in investigation of the binding energies, dispersion and lifetimes of the electronic state on clean metal surface

4. Time-resolved photoemission measurement

5. Time-resolved photoemission measurement

6. Time and Energy Resolution
Heisenberg uncertainty principle

7. Time-resolved photoemission measurement
Figure 2.6: Schematic two dimensional energy diagram of 2PPE with vertical axis rep­
resenting the binding energy (with respect to the Fermi level) and the horizontal a.xis representing the temporal delay between the pump and probe pulses. At negative delay times the UV is the pump and the VIS is the probe. At positive delay times the pulses are reversed

8. Time-resolved photoemission measurement
Transient electronic band structure in TbTe3 monitored by trARPES. Panels (a) and (c) show the excitation of the amplitude mode in weakly perturbative excitation regime, while panels (b) and (d) evidence ultrafast 'melting' of the charge ordered state.

9. Time-resolved photoemission measurement
Studying the unoccupied electronic states of Bi2Se3 by 2PPE. (a) A schematic of the 2PPE processes utilized. Red and blue arrows represent 1.5 eV and 6 eV photons, respectively. (b) Unoccupied electronic structure of Bi2Se3 from the Fermi level to the vacuum level, revealing a second Dirac surface state. (c) Resonant optical excitation of the second surface state using 1.5 eV photons.

10. Experimental setup Time-resolved Pump-Probe Photoelectron Spectroscopy
Time-Resolved ARPES

11. Experimental setup dichroic mirror (β-barium borate)

12. Experimental setup
Schematic illustration of the experimental setup for time-resolved high-harmonic-generation-based XUV-ARPES

13. Light Source
Verdi diode pump laser

14. Experimental set up การปรับ delay time dichroic mirror
dichroic mirror
(β-barium borate)

15. Ultrahigh Vacuum (UHV) Analysis Chamber
TOF
UV-grade fused silica window
Sample of Bi2212 mounted on a 1-inch copper puck
Sample holder

16. Ultrahigh Vacuum (UHV) Analysis Chamber
Ordinary sticky tape is used to cleave the surface of the sample.
2 samples (black spots)
Ultrahigh Vacuum (UHV) Analysis Chamber
checks the sample position through the hemispherical analyser.
transfers a sample from the load lock into the main chamber.
adjusts the manipulator to position the sample for trARPES.

17. Time Of Flight (TOF) Spectrometer
Multichannelplate detector

18. Time Of Flight (TOF) Spectrometer

19. Time Of Flight (TOF) Spectrometer

20. Time Of Flight (TOF) Spectrometer

21. Thank you