Probing anomalous relaxation by coherent multidimensional optical spectroscopy.
We propose to study the origin of algebraic decay of two-point correlation functions observed in glasses, proteins, and quantum dots by their nonlinear response to sequences of ultrafast laser pulses. Power-law spectral singularities and temporal relaxation in two-dimensional correlation spectroscopy signals are predicted for a continuous time random walk model of stochastic spectral jumps in a two-level system with a power-law distribution of waiting times psi(t) approximately t;{-alpha-1}. Spectroscopic signatures of stationary ensembles for 1<alpha<2 and aging effects in nonstationary ensembles with 0<alpha<1 are identified.
Sanda
Frantisek
F
Charles University, Faculty of Mathematics and Physics, Ke Karlovu 5, Prague, 121 16 Czech Republic. sanda@karlov.mff.cuni.cz
Mukamel
Shaul
S
D008962:Models, Theoretical; D011506:Proteins / Q000737:chemistry*; D045663:Quantum Dots; D013057:Spectrum Analysis / Q000379:methods
D011506:Proteins