Bing Gu

I officially start my postdoc position at the University of California, Irvine working with Prof. Shaul Mukamel. I will work on manipulating and controlling chemistry by optical cavities.

Our paper on the relationship between electronic interaction and electronic decoherence is published in J. Chem. Phys. In it, we showed that the electronic interactions do not affect electronic decoherence in the pure-dephasing limit, that is when the electronic transitions between the diabatic states are not significant. 

The book “Nonlinear optics” by Robert W. Boyd is excellent. One can find essentially everything about nonlinear optics in this book. While this book is not written particularly for chemists (as the nonlinear media is not always consist of molecules), majority of the concepts and treatments are beneficial to chemists. The treatment is a combination of quantum mechanics for matter and Maxwell equations for light. The chemists intended to focus on how light changes matter without considering the change of light (the light acts as a parameter in the equations of motion for matter).  But matter also changes light, and we have to combine both views to have a complete picture of laser-matter interaction.

Since I am going to join Prof. Shaul Mukamel group soon, I recently read his book  “Principles of nonlinear optical spectroscopy” again. This is an excellent book for nonlinear spectroscopy in molecules. Although I do think it is a little bit technical in the sense that it goes into the third-order dipole response functions w.r.t. the external electric field. But after getting some familiarity with the mathematical language (i.e. Liouville space pathways), it becomes a wonderful reading experience.

The book “Quantum Mechanics and Path Integrals” by Feynman and Hibbs gives an excellent introduction to the path-integral view of quantum mechanics. This formulation of quantum mechanics, albeit conceptually equivalent to many other formulations, provides a unique perspective to solve problems. One example is that it builds a natural connection to statistical mechanics. And also it has been the foundation of a variety of numerical methods to simulated quantum dynamics for large-scale systems (hundreds of atoms).

It will be an enjoyable reading experience if one has a basic understanding of the quantum mechanics.

I gave a talk at the ACS National meeting at Boston about our work on “Quantifying early time decoherence dynamics through fluctuations” in the information theory session honoring Prof. Levine.  Got excellent questions and comments from students and Prof. Nitzan!

Decoherence is a process where a pure quantum mechanical system (described by a wavefunction) reduces to a statistical mixture of states (described by a density matrix). It is of great relevance for a wide variety of problems in Chemistry and Physics such as quantum-classical transition, relaxation, energy and electron transfer, quantum information and computation. The book “Decoherence: And the Quantum-To-Classical Transition” by Schlosshauer introduces and explains this concept in a very elegant way, that balances math and physical pictures. It is the best book that I have read on decoherence so far.

We submitted a manuscript titled “optical properties of laser-dressed matter”. In it, we introduce a generalized theory for the optical properties of matter driven far from equilibrium by light (i.e. laser-dressed matter), and use it to reveal some striking phenomena of the optical absorption properties of semiconductors driven by non-resonant light. Check it out! 

My work on quantum dynamics, decoherence and non-equilibrium properties of molecules and nanoscale materials is recognized by ACS as the PHYS Young Investigator Award. Thank Ignacio and Sonya for their letters, and the ACS PHYS committee for their efforts and time!

http://www.sas.rochester.edu/chm/news-events/news/2018-06-18-gu-acs-phys-award.html