1. An STM Measures I(r) Tunneling is one of the simplest quantum mechanical process A Laser STM for Molecules Tunneling has transformed surface science. Scanning the field around the molecule is like scanning the tip across a surface -- a molecular STM

2. H 2 ionization in circularly polarized light e p The electron direction determines the field direction at the moment of ionization The bond softened ion determines the molecule’s direction at the moment of ionization

3. COLTRIMS – measuring the 3d-momenta of correlated particles

4. PRL 102, 033004 (2009) The angle-dependent ionization probability

5. Implications of high tunneling rates: “DC” tunneling – The exponent is ~ 30-40. A small change in E i is highly leveraged by the large E a /E(t). Laser tunneling: -- The exponent is ~ 8. The leverage is weakened. Lower orbitals will contribute.

6. PRL 94, 033003 (2005) Measuring excited states

7. The laser STM senses the structure of orbitals: SU1 – direct tunneling SU2 – excitation by bound state interaction with the departing electron  IP~4 eV

8. Applying the “laser STM” to HCl

9. Deeper orbitals tunnel ionize (directly)

10. HCl Two or more orbitals can ionize

11. Transient alignment of molecules time Phys. Rev. A. 68, 023406 (2003)

12. A molecular STM has much more information

13. Normalized Differences Notice: 1 Low lateral momentum structures – tunneling and 2 High lateral momentum structures – elastic scattering Science 3201478 (2008)

14.  p molecule p normal laser The Model: 1.Assume 2.Propagate swarm of electron trajectories classically 3.Including electron-ion interaction 4.Include alignment distribution

15. Low Lateral momentum electrons Science 3201478 (2008)

16. N2N2 O2O2 CO 2 PRL 98, 243001 (2007) The angle dependent probability

17. Transparent Solids:  E = O(10eV) a b c  -SiO 2 Al 2 O 3 LiF crystal structure

18. Extending to Solids? The Lawn Mower Model Self-controlled energy deposition. electron and energy density is predicted. Opt. Express 13, 3208 (2005).

19. Transmission as a function of angle

20. Angle dependent changes in the reduced-mass change the ionization rate. ( /2) ~  m 3 resolution

21. crystalline fused Only the focal region is measured Phys. Rev. Lett. 101, 243001 (2008) 0 amorphous crystal

22. The laser STM Atoms: The filter function using circular polarization. Molecules: The orbital Filtered image of the orbital Quantify the contribution of lower orbitals. Solids: The reduced tunneling mass Measuring crystal symmerty Link to HHG – correlated measurements

23. A mixture of optical and collision science Coherence can be transferred several times between electrons and photons The mixture offers new opportunities for each To optics -- Angstrom spatial imaging. To collision physics -- Time resolution. Bertrand P1, Wörner P3, Meckel

24. Three new forms of nonlinear spectroscopy 1Tunneling (to characterize orbitals) 2Elastic scattering or Laser Induced Electron Diffraction (to determine nuclear positions) – see Meckel et al. 3Interferometry (to image orbitals -- photoelectron spectroscopy in reverse) – see poster by Bertrand P1 and Wörner P3

25. The tunneling electron wave packet of O 2