Cyclotron resonance spectroscopy in a high mobility two dimensional electron gas using characteristic matrix methods

Area of Science:

• Condensed Matter Physics
• Quantum Materials Science

Background:

• Cyclotron resonance experiments in high-mobility two-dimensional electron gases (2DEGs) are crucial for understanding electron dynamics.
• Direct interference between primary and satellite reflections has historically limited frequency resolution in these experiments.

Purpose of the Study:

• To develop a novel characteristic matrix-based method for analyzing cyclotron resonance experiments.
• To overcome the limitations imposed by signal interference in terahertz time-domain spectroscopy (THz-TDS) of 2DEGs.
• To accurately determine the cyclotron dephasing lifetime in 2DEG samples.

Main Methods:

• Development of a characteristic matrix-based analysis method.
• Simulation of experimental data obtained via terahertz time-domain spectroscopy (THz-TDS).
• Analysis of THz-TDS data exhibiting multiple substrate pulses with a 15 ps separation.

Main Results:

• The new method successfully simulates experimental data affected by signal interference.
• A cyclotron dephasing lifetime of 15.1 ± 0.5 ps was determined at 1.5 K.
• A cyclotron dephasing lifetime of 5.0 ± 0.5 ps was determined at 75 K.

Conclusions:

• The characteristic matrix method provides enhanced frequency resolution for cyclotron resonance studies.
• The determined cyclotron dephasing lifetimes offer insights into electron scattering mechanisms at different temperatures.
• This approach advances the analysis of THz-TDS experiments in 2DEG systems.