Allgemeines Physikalisches Kolloquium im Wintersemester 2012/2013
Ort:     48149 Münster, Wilhelm-Klemm-Str. 10, IG I, HS 2,
Zeit:    Donnerstag, 06.12.2012 16:00 Uhr c.t.
Kolloquiums-Kaffee ab 15:45 Uhr vor dem Hörsaal

Attosecond physics at a nanoscale tip
Dr. Peter Hommelhoff, MPI für Quantenoptik, Garching

Laser pulses have nowadays reached durations as short as single or few optical cycles.
In addition, the optical carrier field can be now be controlled. These achievements have
opened the field of attosecond physics (1 as = 10^-18 s), in which the control of the optical
electric field of well-controlled few cycle laser pulses is utilized to control the motion of
photo-emitted electrons on the attosecond time scale, and on Ångstrom and nanometer
distance scales. Until recently, this has only been possible with atoms or molecules in
the gas phase. We could show that the same physics can be observed at nanometric
metal tips: We observe high order above-threshold photoemission and strong-field effects
[1], re-scattering of electrons at the surface of the tip [2], and field dependent matter-
wave interference of electrons in the time-energy domain [3,4] − hallmarks of
attosecond physics, observed at a solid. We envision new surface imaging techniques,
as well as the realization of an ultrafast current switch, the attosecond field effects transistor.
Furthermore, the merger of near-field optics and plasmonics with strong-field
physics promises intriguing effects to be observed soon.

[1] Schenk, Krüger, Hommelhoff, PRL 105, 257601 (2010)
[2] Wachter, Lemell, Burgdörfer, Krüger, Schenk, Hommelhoff, PRB, in the press, arxiv:1201.0462
[3] Krüger, Schenk, Hommelhoff, Nature 475, 78 (2011)
[4] Krüger, Schenk, Förster, Hommelhoff, J. Phys. B. 45, 074006 (2012)

Einladender: Prof. Dr. Guido Schmitz

Im Auftrag der Hochschullehrer des Fachbereichs Physik

Prof. Dr. Nikos Doltsinis