nonlinear spectroscopy characterizing fluctuations n.
Skip this Video
Loading SlideShow in 5 Seconds..
Nonlinear Spectroscopy: Characterizing Fluctuations PowerPoint Presentation
Download Presentation
Nonlinear Spectroscopy: Characterizing Fluctuations

Loading in 2 Seconds...

  share
play fullscreen
1 / 20
Download Presentation

Nonlinear Spectroscopy: Characterizing Fluctuations - PowerPoint PPT Presentation

irina
168 Views
Download Presentation

Nonlinear Spectroscopy: Characterizing Fluctuations

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Nonlinear Spectroscopy:Characterizing Fluctuations Andrei Tokmakoff MIT Department of Chemistry 2009

  2. Fluctuations in lineshapes

  3. System-Bath Interactions • System: Spectroscopically Bright States • Bath: Dark States • → Energy Gap Fluctuations • In spectroscopy … (Condon Approx.)

  4. Energy Gap Fluctuations • Energy Gap Correlation Function • Dipole Correlation Function → Absorption lineshape • Second Cumulant approx.

  5. A bath of arbitrary form • Spectral Density • Brownian Oscillator Model

  6. Nonlinear response for fluctuating system • Following earlier approach: • Cumulant approximation:

  7. Two pulse echo ~1/D

  8. Two pulse echo

  9. Lens analogy

  10. Three pulse echoes: Peak shift

  11. 2D Lineshapes

  12. Spectral Diffusion and Waiting Time

  13. Time-domain 2D Spectroscopy

  14. Time-Domain: Echo shape

  15. 2D IR Relaxation Experiment Probes Spectral Diffusion

  16. Ellipticity

  17. Correlation of Spectral Broadening

  18. Correlation Effects in 2D IR Spectra

  19. Correlated Energy Fluctuations Frequency Auto- and Cross-Correlation Functions: