Excitons are electrically neutral quasiparticles with some unique particularities. Now, in a new study, scientists from Tel Aviv University captured these quantum particles’ movements in high resolution using a new imaging device. These quasiparticles exist only in semiconductor and insulating materials and are accessible in 2D materials of only a few atoms thick.
Led by Prof. Haim Suchowski and Dr. Michael Mrejen, both from Tel Aviv University, the new research focused on excitons quantum particles’ generation and propagation in 2D materials in a very small timeframe and at high resolution.
“Our new imaging technology captures the movement of excitons in a short time frame and at a nanometer scale,” said Dr. Mrejen, one of the two authors of the study published in Science Advances. “This tool can be extremely useful for peeking into a material’s response at the very first moments light has affected it,” he added.
Quantum Particles’ Movements Captured In High Resolution, Thanks To A New Imaging Device
“Such materials can be used to significantly slow down light to manipulate it or even store it, which are highly sought-after capabilities for communications and for photonics-based quantum computers,” also explained Prof. Suchowski, the other author of the study.
“From the instrument capability point of view, this tour de force opens up new opportunities to visualize and manipulate the ultrafast response of many other material systems in other spectrum regimes, such as the mid-infrared range in which many molecules are found to vibrate,” Suchowski added.
By creating a unique spatiotemporal imaging technique at the femtosecond-nanometric scale, the researchers managed to observe exciton-polariton dynamics in tungsten diselenide. In short, they saw those quantum particles’ movements in unprecedented high resolution.
“We knew we had a unique characterization tool and that these 2D materials were good candidates to explore interesting behavior at the ultrafast-ultrasmall intersection. I should add that the material, tungsten diselenide, is extremely interesting from an applications point of view. It sustains such light-matter coupled states in very confined dimensions, down to single atom thickness, at room temperature and in the visible spectral range,” concluded Dr. Mrejen.