Ultrafast Spectroscopy in High Magnetic Fields Using a Mini-coil Pulsed Magnet

[摘要] We have developed a unique magneto-optical system combining intense ultrashort laser pulses, low temperatures, and high magnetic fields up to 30 T with a table-toppulsed mini-coil magnet. With this unique system, we investigated the carrier and emission dynamics of a population-inverted InGaAs semiconductor multiple quantumwell sample under extreme conditions. At low temperatures and zero magnetic field, we observe a bright line of emission from an electron-hole plasma with dynamically changing photon energy. We attribute this bright emission to amplified spontaneous emission with enhanced gain at the dynamically changing Fermi edge as the carriers relax to the ground state. Previously, we have demonstrated superfluorescent emission from this sample at high magnetic fields up to 17.5 T using a DC magnet at the National High Magnetic Field Laboratory in Tallahassee, FL. With our new system, we have extended our studies to higher magnetic fields and with improved temporal resolution because of the unique mini-coil design of our magnet system.

[发布机构] Rice University

[效力级别] spectrscopy