Naujienos ir renginiai


2019. 10. 15 -

Jungtinis cheminės fizikos seminaras. Jianshu Cao

2019-10-15 14:00 NFTMC D401 auditorijoje vyks Jungtinis cheminės fizikos seminaras:

Exciton Dynamics and Spectra of Molecular Aggregates
Jianshu Cao (Department of Chemistry, MIT)

(I) Calculations of coherent quantum transport in disordered systems reveal an optimal diffusion constant at an intermediate level of noise and temperature. [1] Polaron calculations suggest the crucial role of localization length in coherent transport and predict charge mobility close to experimental values. [2] Further, we have explored the dependence on the dimensionality and shape of the samples and demonstrated the universal scaling of the 1D-2D transition in the diffusion of nanotubes [3]. Though transport is suppressed by disorder, measurements such as dissociation rate or trapping rate can be enhanced by disorder. [4]

(II) Spectroscopic measurements of nanotubes and 2D systems allow us to classify the structure of dipolar lattices beyond the simple rule of H and J aggregates. [5] Further, we have 
obtained the universal scaling laws in the spectral shift, splitting, and width, and related them to the structure of molecular aggregates. [5,6]
  1. “Coherent quantum transport in disordered systems (I): The influence of dephasing on the transport properties and absorption spectra on one-dimensional systems” Moix, Khasin, Cao, New Journal of Physics, 15, 085010 (2013)
  2. Coherent quantum transport in disordered systems (A unified polaron treatment of hopping and band-like transport” Lee, Moix, Cao, JCP 142, 164103 (2015) III):
  3. Quantum diffusion on molecular tubes: Universal scaling of the 1D to 2D transition“oix, ”. Chuang, Lee, MKnoester, and Cao, Phys. Rev. Lett. 116, 196803 (2016)
  4. Generic mechanism of optimal energy transfer efficiency: A scaling theory of the mean first-passage time in exciton systems” Wu, Silbey, Cao, Phys. Rev. Lett 110 (20), 200402 (2013)
  5. Generalized Kasha's Scheme for Classifying Two-Dimensional Excitonic Molecular Aggregates: Temperature Dependent Absorption Peak Frequency Shift” Chuang, Bennett, Caram, Aspuru-Guzik, Bawendi, J Cao, accepted by CHEM. (2019)
  6. “Construction of multichromophoric spectra from monomer data: Applications to resonant energy transfer”. Chenu and Cao, Phys. Rev. Lett. 118, 013001 (2017)

Organizuoja: MDFS (FTMC) ir Cheminės fizikos institutas (FF, VU).
Kontaktai: ir