Dr. Liang-Yan Hsu

Dr. Liang-Yan Hsu, IAMS Assistant Research Fellow, received his Ph.D. at Princeton University under the tutelage of Prof. Herschel Rabitz. After a postdoctoral fellowship with Prof. George Schatz’s group at Northwestern University, he joined IAMS in July 2017. His research field is theoretical chemical physics and nanoelectronics. Today we visited him to hear more.

A: What is chemical physics? What do you mean by “theoretical?”

Dr. Liang-Yan Hsu (LYH): Chemical physics is a branch of physics and chemistry that investigates chemical processes or the physical properties of materials from the point of view of physics. For instance, when we study molecular fluorescence and electron transfer, we start from a microscopic world based on the principles of quantum mechanics, statistical mechanics, and electrodynamics. As for “theoretical,” it means that we explore and analyze chemical processes by using mathematical equations and computers.

A: What specific topic are you working on in the field of theoretical chemical physics?

LYH: I am working on two topics. The first is resonance energy transfer and molecular fluorescence in nanostructures. The second is photoinduced electron transport through molecules.

A: Why did you select these two topics? Could you talk more about them?

LYH: Resonance energy transfer and molecular fluorescence are fundamental photophysical processes, and there are a lot of applications based on the two processes. The pioneers have established a variety of useful theories about the two processes, but their theories cannot be adequately employed to describe molecules coupled to plasmon polariton or photons in an inhomogeneous cavity. To address this issue, we introduced a technique called “macroscopic quantum electrodynamics.” My recent works have received broad interest and a lot of attention. For example, “Plasmon-Coupled Resonance Energy Transfer” was selected as a feature article in The Journal of Physical Chemistry Letters and “Quantum Dynamics of a Molecular Emitter Strongly Coupled with Surface Plasmon Polaritons: A Macroscopic Quantum Electrodynamics Approach” was chosen as “Editor’s Pick” and “Editor’s Choice” in The Journal of Chemical Physics.

A: How about the other topic, “photoinduced electron transport through molecules?”

LYH: Photoelectric processes have many applications, such as solar cells. Chemists have investigated organic solar cells for a long time, but the photoelectric processes in molecules are still not very clear. By using advances in technology, currently, researchers can study the photoelectric process at a single-molecule level. As a result, it is a good opportunity to clarify the mechanism of photoelectric processes in organic molecules. If we can fully understand the mechanism, we may increase the efficiency of organic solar cells. If you are interested in this topic, you can read my recent work “Photoinduced Anomalous Coulomb Blockade and the Role of Triplet States in Electron Transport through an Irradiated Molecular Transistor” in Nano Letters.

A: Your research topics seem quite challenging. Do you have any group members or need financial support?

LYH: Yes, I have a fantastic team. I am very impressed by my students and my postdocs. The members of my group are enthusiastic about their research work, and truly love science. Finally, I would like to acknowledge the support from IAMS and Academia Sinica. In my early career, our director Prof. Kuei-Hsien Chen fully supports my research directions, and my mentors Prof. Ching-Ming Wei and Prof. Yuh-Lin Wang give useful advice. Without their support, I could not have started my research career in Taiwan. IAMS is a fantastic institute for basic science. I think that it is one of the best choices for young rising scientists.

Dr. Hsu and his fantastic, hardworking team