Researchers have made a significant breakthrough in simulating molecular electron transfer, a vital process that is essential to many physical, chemical, and biological phenomena. The study, which appears in Science Advances, showcases the application of a trapped-ion quantum simulator to model electron transfer dynamics with exceptional flexibility, opening new avenues for research in areas like molecular electronics and photosynthesis.
Researchers at Rice University have made a significant breakthrough in the simulation of molecular electron transfer, a key process that is essential to numerous physical, chemical, and biological phenomena. The study, published in Science Advances, describes the use of a trapped-ion quantum simulator to model electron transfer dynamics with extraordinary tunability, paving the way for fresh research opportunities in fields ranging from molecular electronics to photosynthesis.
Electron transfer plays a crucial role in processes like cellular respiration and energy capturing in plants, yet it has long been a complex challenge for scientists due to intricate quantum interactions. Current computational methods often do not adequately represent these processes. The interdisciplinary team at Rice, comprising physicists, chemists, and biologists, tackled these challenges by developing a programmable quantum system that can independently control essential factors in electron transfer, such as donor-acceptor energy gaps, electronic and vibronic couplings, and environmental dissipation.
By utilizing an ion crystal confined within a vacuum system and manipulated using laser light, the researchers showcased the capability to simulate real-time spin dynamics and assess transfer rates under varying conditions. These results not only confirm important theories in quantum mechanics but also offer new perspectives on light-harvesting systems and molecular devices.
“This is the first instance of such a model being simulated on a physical device while factoring in the environment and even customizing it in a controlled manner,” stated lead researcher Guido Pagano, an assistant professor of physics and astronomy. “This marks a significant advancement in utilizing quantum simulators to delve into models and conditions that are crucial for chemistry and biology. The goal is to harness quantum simulation to explore scenarios that classical computational techniques cannot access.”
The team achieved a notable milestone by successfully reproducing a standard model of molecular electron transfer using their programmable quantum platform. Through finely tuned dissipation, they investigated both adiabatic and nonadiabatic phases of electron transfer, illustrating how these quantum effects function under different circumstances. Their simulations also pinpointed optimal conditions for electron transfer, aligning with energy transport methods seen in natural photosynthetic systems.
“Our research is motivated by the question: Can quantum hardware be used for direct simulation of chemical dynamics?” Pagano said. “In particular, can we incorporate environmental influences into these simulations, as they play vital roles in critical life processes like photosynthesis and electron transfer in biological molecules? Answering this question is crucial, as it could yield valuable insights for the creation of new light-harvesting materials.”
The practical implications of this research are extensive. Gaining a deep understanding of electron transfer at this level could lead to advancements in renewable energy technologies, molecular electronics, and the creation of innovative materials for quantum computing.
“This experiment represents a promising first step in comprehending how quantum effects affect energy transport, particularly in biological systems like photosynthetic complexes,” noted Jose N. Onuchic, co-author of the study and the Harry C. and Olga K. Wiess Chair of Physics. “The insights gained from experiments of this nature could lead to the design of more efficient light-harvesting materials.”
Peter G. Wolynes, another co-author of the study and a professor at the D.R. Bullard-Welch Foundation, highlighted the broader implications of the findings: “This research forms a connection between theoretical predictions and experimental validation, providing a highly tunable framework to explore quantum processes within complex systems.”
The research team aims to broaden their focus to more intricate molecular systems, including those involved in photosynthesis and DNA charge transport. They also hope to examine the impact of quantum coherence and delocalization on energy transfer, utilizing the unique features of their quantum platform.
“This is just the start,” expressed Han Pu, co-lead author of the study and a professor of physics and astronomy. “We are eager to explore how this technology can unravel the quantum mysteries of life and more.”
The study’s other contributors include graduate students Visal So, Midhuna Duraisamy Suganthi, Abhishek Menon, Mingjian Zhu, and research scientist Roman Zhuravel.
This research was supported by funding from the Welch Foundation Award C-2154, the Office of Naval Research Young Investigator Program (No. N00014-22-1-2282), a National Science Foundation CAREER Award (No. PHY-2144910), the Army Research Office (W911NF22C0012), the Office of Naval Research (No. N00014-23-1-2665), the NSF (PHY-2207283, PHY-2019745 and PHY-2210291), and the D. R. Bullard-Welch Chair at Rice (No. C0016). The authors also acknowledge support from the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under the Early Career Award No. DE-SC0023806. The isotopes used in the research were provided by the U.S. Department of Energy Isotope Program managed by the Office of Isotope R&D and Production.
