Graham Fleming
Chemist Senior Faculty Scientist
Research Interests
Our group uses and develops advanced multidimensional ultrafast spectroscopic methods to study complex systems such as natural photosynthetic complexes, liquids, solution, and nanoscale systems such as single-walled carbon nanotubes.
In natural photosynthetic systems we aim to define the design principles underlying their remarkable .quantum efficiencies, and to use these principles to aid in the design of robust and efficient artificial photosynthetic devices. Natural systems are also regulated in response to external conditions, such as light levels, and one of the key components of Photosystem II is regularly repaired. We plan to understand the control system at the molecular level by combining molecular genetics biochemistry, modeling, and ultrafast spectroscopy through collaboration with Professor K. K. Niyogi. We have recently shown, using two-dimensional electronic spectroscopy, that long lived electronic quantum coherence exists in photosynthetic light harvesting complexes. We are exploring the implications of quantum coherence for photosynthesis and for quantum information science.
The electronic properties and excited state dynamics of nanoscale materials with significant quantum confinement effects yield a rich range of properties and potential applications. We aim to understand these properties with a particular current emphasis on single-walled carbon nanotubes via non-linear ultrafast spectroscopy and theoretical modeling.
The modern theoretical description of photochemical processes, in particular what determines which products are formed, has at its core relaxation through conical intersections. Yet very little experimental information is available on such processes. Two dimensional electronic spectroscopy has the potential to provide a window into these processes and experiments to explore conical intersection dynamics are under development.
Ultrafast multidimensional electronic spectroscopy is in its infancy with many potential ways to enhance resolution, sharpen the information content and extract specific dynamical pathways (e.g., those that involve only coherence). My group continues to develop new spectroscopic methods and the theoretical tools for their analysis.
Recent Publications
Related News
How Algae Use Memory to Adapt to Sudden Changes in Sunlight
A new study co-led by Graham Fleming a senior faculty scientist in the Molecular Biophysics and Integrated Bioimaging (MBIB) Division, and Krishna Niyogi, a faculty scientist in MBIB, reveals the precise molecular machinery that underpins photoprotective memory in green algae. The results may help scientists develop more productive plants and improve crop yields.
Photosynthesis, Key to Life on Earth, Starts with a Single Photon
A new study by an interdisciplinary team led by Molecular Biophysics and Integrated Bioimaging senior faculty scientist Graham Fleming and Energy Sciences Area senior faculty scientist Birgitta Whaley, and published in Nature today, confirms for the first time that a single photon–the smallest quantity of light possible–can initiate the first step of photosynthesis, one of nature's essential processes.
Sauer Leaves Legacy in Science and Teaching
As a young man, Kenneth Sauer joined Berkeley Lab four years after arriving in Berkeley for his postdoctoral position with famed chemist Melvin Calvin. By that time, he had accepted an assistant professorship in UC Berkeley’s Department of Chemistry to continue what would be his life’s scientific work on the intricate physical process of photosynthesis. He remained active for over 50 years and was, most recently, a professor emeritus of chemistry at UC Berkeley. Sauer died at the age of 91 following a brief illness on November 6, 2022.
