Just Like Flipping a Switch—in Only Half a Picosecond
January 17, 2019 | University of MissouriEstimated reading time: 2 minutes
Solar cells, quantum computing and photodynamic cancer therapy. These all involve molecules switching between magnetic and nonmagnetic forms. Previously this process, called a “spin flip,” was thought to occur slowly in most cases. Now, researchers at the University of Missouri have discovered spin flips happen in one half of one trillionth of a second, or half a picosecond in the course of a chemical reaction. To understand how fast it is — watches count in seconds, sporting games are timed in 10ths of a second, and light travels just under 12 inches in one-billionth of a second. Spin flips are faster.
“A typical molecule can have two modes, either magnetic or non-magnetic,” said Arthur Suits, a professor of chemistry in the MU Department of Chemistry. “They can switch from one mode to another if they are ‘excited’ such as by absorbing light. Most molecules begin as non-magnetic, but if you excite it with light, it can switch and become a magnetic molecule, or vice versa.”
It is well known that the spin flip for molecules excited by light is usually inefficient so it happens very slowly. Spin flips in chemical reactions are possible but few examples are known. Suits and his team at the University of Missouri tested whether spin flips could occur during a reaction by conducting a scattering experiment where beams of molecules collided into one another, creating a chemical reaction inside a vacuum chamber. They were surprised by what they discovered and partnered with Spiridoula Matsika, a professor of computational theory in the Department of Chemistry at Temple University to understand why the spin flip occurs in half of a trillionth of a second, much faster than previously thought.
“We discovered this transition from magnetic to non-magnetic happens after the chemical reaction, as the molecules are coming apart and products are forming,” Suits said. “With this theory, we can understand and explain why this is happening very efficiently in the course of this chemical reaction.”
The researchers say understanding this behavior is fundamental for many areas in science such as making more efficient solar cells, quantum computing and photodynamic cancer therapy.
The study, “Intersystem crossing in the exit channel,” was published in Nature Chemistry. Other collaborators on this study include Hongwei Li, a postdoctoral fellow at MU and Alexander Kamasah. Kamasah, a doctoral student at MU during the study, is now an assistant professor of chemistry at Rose-Hulman Institute of Technology in Terre Haute, Indiana. Funding for this study was provided by a U.S. Department of Energy contract (DE-SC0017130) along with an Army Research Office grant (W911Nf-17-1-0099) and a National Science Foundation grant (CHE-1800171). The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies.
Suggested Items
D Coupon Testing and Data Insights With GreenSource Fabrication
04/17/2024 | Marcy LaRont, PCB007 MagazineMarcy LaRont spoke with Steve Karas of GreenSource Fabrication at the SMTA UHDI conference in March. He presented a case study that GreenSource undertook with a customer on critical via reliability with advanced materials and used the experience to highlight the importance and effectiveness of D coupon testing. He also discussed GreenSource’s approach to data aggregation and a new system they developed to use collected data effectively.
Real Time with... IPC APEX EXPO 2024: Exploring Silicone Solutions with R&D Director of CHT
04/17/2024 | Real Time with...IPC APEX EXPOIn this interview, Gerry Ellis, the R&D director for CHT, discusses the product range offered by his company. He explains the challenges in creating base formulations, the drive to make products more user-friendly, and the various application techniques involved. Ellis also highlights the key market segments and the significance of providing efficient solutions to customers.
The World of Electronics and Standards: A Conversation with Frank Honyotski, STI
04/03/2024 | Marcy LaRont, PCB007 MagazineMarcy LaRont of I-Connect007 speaks with Frank Honyotski of STI Electronics, who discusses the services offered by STI, including training, engineering, and failure analysis. He highlights his involvement with IPC standards development and emphasizes the importance of industry professionals engaging in standards development.
Demand Rebounds, Global LED Industry Revenue Expected to Grow 3% in 2024 with Market Focus on Automotive Displays
04/01/2024 | TrendForceTrendForce’s latest LED industry report indicates that the global market is set to recover in 2024, with estimated revenues reaching US$13 billion—marking a YoY growth of 3%.
Orbex Secures Patent for 'Petal Fold' Reusable Rocket Technology
03/29/2024 | OrbexOrbex has successfully patented its REFLIGHT reusable rocket technology following patent approval in several European markets, based on the patent grant by the European Patent Office, as well as in the United States.