Greater Boston Area Theoretical Chemistry Lecture Series

2017-2018 Speaker Schedule

Reduced Hierarchal Equations of Motion Approach to Multi-dimensional Spectroscopies

09/13/17 4:15pm

MIT Building 4, Room 237

Yoshitaka Tanimura

Kyoto University, Japan




Yoshitaka Tanimura

Quantum coherence and its dephasing or relaxation by coupling to an environment plays an important role in nonadiabatic transitions, photoexcitation and tunneling processes. I first introduce a system-bath model to explain how fluctuation and dissipation arises from the environment, and the concept will be illustrated with some examples from chemistry and biology. Then I derive the quantum hierarchal Fokker-Planck equations (QHFPE) on the basis of the Feynman-Vernon influence functional formalism, which can deal with strong system-bath coupling and non-Markovian noise.
By applying hierarchal formalism to multi-electric states, we can investigate laser excitation and photoisomerization process described by multi-electric state numerically rigorously. As an example, we computed Wigner distributions for excited, ground, and coherent states. We then investigated excited state dynamics involving transitions among these states by analyzing electronic spectra with various values of the heat bath parameters. Our results provide predictions for spectroscopic measurements of photoexcitation and photoisomerization dynamics.
References
Y. Tanimura, Real-Time and Imaginary-Time Quantum Hierarchal Fokker-Planck Equations, J. Chem. Phys. 142, 144110 (2015).
T. Ikeda and Y. Tanimura, Probing photoisomerization processes by means of multi-dimensional electric spectroscopy: The Multi-state quantum hierarchal Fokker-Planck Equation approach, J. Chem. Phys. 146, 014102 (2017)

The Dynamics of Coupled Nuclear-Electronic Motion: At the Intersection of Statistical Mechanics, Electronic Structure Theory, and Solid State Physics

10/25/17 4:15pm

MIT Building 4, Room 237

Joe Subotnik

University of Pennsylvania




Joe Subotnik


In this talk, I will give an overview of the theory of mixed quantum-classical nuclear-electronic motion both in solution and at metal surfaces, focusing on both stochastic and mean-field descriptions. This theory gives a clear and intuitive picture of electronic relaxation in a condensed environment, e.g. how photo-excitation can lead to macroscopic charge transfer and how the second law of thermodynamics (i.e. entropy growth) emerges from microscopically reversible dynamics. I will attempt to give an introductory but also deep account of this rich field of study. Towards the end, I will highlight open questions, especially at metal surfaces, where propagating ab initio calculations remains very daunting.

TBD

02/07/18 4:15pm

MIT Building 4, Room 237

Revati Kumar

Louisiana State University




Revati Kumar


TBD

TBD

02/14/18 4:15pm

MIT Building 4, Room 237

Yuji Sugita

RIKEN, Japan




Yuji Sugita


TBD

TBD

02/28/18 4:15pm

MIT Building 4, Room 237

Tim Berkelbach

University of Chicago




Tim Berkelbach


TBD

TBD

03/14/18 4:15pm

MIT Building 4, Room 237

Ignacio Franco

University of Rochester




Ignacio Franco


TBD

TBD

03/28/18 4:15pm

MIT Building 4, Room 237

James Kindt

Emory University




James Kindt


TBD

TBD

04/11/18 4:15pm

MIT Building 4, Room 237

John Stanton

University of Florida




John Stanton


TBD

TBD

05/02/18 4:15pm

MIT Building 4, Room 237

Mark Gordon

Iowa State University




Mark Gordon


TBD

TBD

05/16/18 4:15pm

MIT Building 4, Room 237

Trygve Helgaker

University of Oslo, Norway




Trygve Helgaker


TBD

Past Schedules