Testing the Tomographic Fermi Liquid Hypothesis with High-Order Cyclotron Resonance.

Area of Science:

• Condensed matter physics
• Quantum materials
• Electron hydrodynamics

Background:

• The tomographic Fermi liquid (TFL) hypothesis suggests distinct relaxation dynamics for odd and even angular harmonics of the electron distribution function in 2D systems.
• Experimental validation of TFL has been challenging due to limitations of traditional transport measurements.

Purpose of the Study:

• To experimentally verify the tomographic Fermi liquid (TFL) hypothesis.
• To establish high-order cyclotron resonance (CR) as a method for probing electron relaxation dynamics.

Main Methods:

• Theoretical modeling of electron relaxation in 2D systems.
• Terahertz photoconductivity measurements in graphene.
• Analysis of linewidths in high-order cyclotron resonance spectra.

Main Results:

• The linewidth of the mth cyclotron resonance (CR) peak was found to directly correlate with the relaxation rate of the corresponding angular harmonic (γm = 1/τm).
• Measurements in graphene revealed that the third-order CR peak has a narrower linewidth than the second-order CR peak (τ3 > τ2).
• This observed hierarchy of relaxation times supports the TFL predictions.

Conclusions:

• High-order cyclotron resonance provides a direct experimental probe for electron relaxation times of different angular harmonics.
• The findings provide definitive evidence for the tomographic Fermi liquid regime in graphene.
• This work establishes high-order CR as a valuable technique for studying hydrodynamic transport in quantum materials.