Graduate School in Nonlinear Science

Sponsored by The Danish Research Agency

MIDIT                              OFD                          CATS
Modelling, Nonlinear Dynamics      Optics and Fluid Dynamics    Chaos and Turbulence Studies
and Irreversible Thermodynamics    Risø National Laboratory     Niels Bohr Institute and 
Technical University of Denmark    Building 128                 Department of Chemistry
Building 321                       P.O. Box 49                  University of Copenhagen 
DK-2800 Lyngby                     DK-4000 Roskilde             DK-2100 Copenhagen Ø
Denmark                            Denmark                      Denmark


by Dr. Peter Hamm
Max Born Institut,
Max Bornstr. 2A,
12489 Berlin, Germany,

MIDIT-seminar 488

Tuesday, May 8, 2001, 14.00 h
at IMM, Bldg. 305, Room 018, DTU

Abstract: It has been speculated many years ago that delocalized and/or self- localized vibrational states in alpha-helices might play an important role for one of the most remarkable - yet not understood - property of proteins and enzymes, namely their capability to store and transport small quanta of energy in an extremely efficient manner. We are utilizing nonlinear femtosecond spectroscopic methods with the aim to understand the nature of these states and the coupling mechanisms giving rise to them. Since the nonlinear spectroscopic response of a harmonic system vanishes exactly, these experiments are particularly sensitive to the nonlinearities of the molecular Hamiltonian. Different coupling mechanisms are discussed on several examples, such as tri-peptides, alpha-helices and crystalline acetanilid (ACN), which is a commonly used model system for quasi-one- dimensional chains of hydrogen bonded peptide units.