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Novel Analysis Method Leads to the Discovery of Ultrafast Magnetic Switching

Novel Analysis Method Leads to the Discovery of Ultrafast Magnetic Switching

Researchers at the University of Konstanz recently discovered a novel type of magnetic switching that occurs on ultrafast timescales. This ultrafast switching would have been seen as experimental noise in previous research endeavors, however with a novel analytical method the researchers have observed and analyzed the switching for the first time. 



Antiferromagnets, magnetic materials in which the magnetization of sub-lattices cancel out each other, are a promising potential insulator for energy-efficient tech components. However, due to their lack of external magnetic fields, they are difficult to physically characterize. In their research, published in Nature Communications, the researchers analyzed the small magnetic fluctuations surrounding these antiferromagnets.



At the Collaborative Research Centre 1432 (CRC), the researchers first needed to develop a method for observing these fluctuations on an ultrafast time scale.  The method developed relies on pulse sequence or pulse pair lasers to measure the minute magnetic fluctuations, a technology first developed for investigating quantum fluctuations that has recently been expanded into the field of magnetic systems. 



During the experiment, the researchers used two ultrashort light pulses that were transmitted through the magnet with a time delay. The magnetic properties of the Antiferromagnets were analyzed during the transit time of each pulse. The first pulse serves as a reference while the second pulse contains information regarding changes to the antiferromagnet between the two pulses. 



After gathering the data and computation modeling of the experiment, the researchers discovered telegraph noise on an ultrashort time scale. These findings mean that not only is there unsorted noise, but there are also fluctuations in which the system switches between two well-defined states. These fast random switches have never been observed before and could have interesting applications in the future for uses such as random number generation.