Exploring Two-dimensional Electron Gases at Extreme Magnetic Fields with Optical and Terahertz 2DFT spectroscopy

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Non-technical: This project elucidates the fundamental properties of solid matter at extreme conditions, such as low dimensions and extremely high magnetic fields. The scientific understanding of the fundamental properties of these materials is crucial for the next generation of electronic devices and a 21st century economy. The project also leads to efficient training of undergraduate and graduate students who will be future leaders in scientific discovery in academia, national labs, and industry. In particular, students are trained on electronic materials, laser science and applications, and high magnetic fields. Minority middle school students in Florida and Alabama are exposed to cutting edge scientific research. Technical: This research project will focus on the joint investigation by researchers at the USF and the UAB to elucidate the coherence lifetimes in high mobility modulation doped GaAs\AlGaAs systems. The USF team will perform two-dimensional Fourier transform (2DFT) experiments, which are an enhanced form of coherent four-wave mixing measurements that are similar to the extension of nuclear magnetic resonance to two dimensions. The UAB team will develop a new terahertz frequency spectrometer that will employ well-established techniques to generate high peak power terahertz pulses using nonlinear difference frequency generation in the tilted wavefront configuration and a multiple pulse technique similar to the near infrared 2DFT techniques. Both experiments will use the new Split Helix magnet to perform measurements at 25 T, which was custom-designed by National High Magnetic Field Lab researchers to enable next generation optical measurements. This new magnet will enable the USF-UAB collaboration to study quantum coherence in high mobility electron gases in field ranges that were inaccessible to ultrafast-laser source based experiments.This project will contribute to our understanding of decoherence mechanisms and both inter- and intra-Landau level coherence, which is critical to their utilization in next generation electronics. The research team is committed to the broad dissemination of the results of this research project through presentations, internationally-attended research conferences, and publication of our results in high impact, peer-reviewed journals. Both USF and UAB researchers are strongly committed to fostering the education of the next generation of condensed matter and high magnetic field researchers. To contribute to these NSF goals, we will directly involve undergraduate, summer REU students, and our graduate students in the design, planning, experiments, data analysis and the from traditionally underrepresented groups from our diverse student bodies.