Coherent two-dimensional Fourier transform spectroscopy using a 25 Tesla resistive magnet

Abstract

We performed nonlinear optical two-dimensional Fourier transform spectroscopy measurements using an optical resistive high-field magnet on GaAs quantum wells. Magnetic fields up to 25 Tesla can be achieved using the split helix resistive magnet. Two-dimensional spectroscopy measurements based on the coherent four-wave mixing signal require phase stability. Therefore, these measurements are difficult to perform in environments prone to mechanical vibrations. Large resistive magnets use extensive quantities of cooling water, which causes mechanical vibrations, making two-dimensional Fourier transform spectroscopy very challenging. Here we report on the strategies we used to overcome these challenges and maintain the required phase-stability throughout the measurement. A self-contained portable platform was used to setup the experiments within the time frame provided by a user facility. Furthermore, this platform was floated above the optical table in order to isolate it from vibrations originating from the resistive magnet. Finally, we present two-dimensional Fourier transform spectra obtained from GaAs quantum wells at magnetic fields up to 25 Tesla and demonstrate the utility of this technique in providing important details, which are obscured in one dimensional spectroscopy.

Time-Domain Terahertz Spectroscopy in High Magnetic Fields

“…The minimum experimentally accessible temperature is 5 K. The magnetic field is generated perpendicular to the optical access, making it well-designed for experiments in the Voigt geometry. To access the Faraday geometry, custom sample holders can be used to steer the beam inside the magnet to be parallel to the field [68]. Recently, this magnet has been used to perform optical-pump THz-probe studies of GaAs quantum wells in magnetic fields up to 25 T [57].…”