Multiple Mechanisms for Emerging Conductance Plateaus in Fractional Quantum Hall States

Area of Science:

• Condensed Matter Physics
• Quantum Physics

Background:

• Two-terminal conductance quantization in quantum Hall (QH) physics is traditionally linked to chiral edge modes.
• The orthodox theory suggests quantized plateaus result from full transmission/reflection of these modes.

Purpose of the Study:

• To demonstrate that quantized plateaus can manifest from different underlying mechanisms.
• To show that conductance measurements alone are insufficient to differentiate these mechanisms.
• To introduce shot noise measurements as a method for distinguishing QH mechanisms.

Main Methods:

• Theoretical analysis of two-terminal conductance.
• Investigation of shot noise (auto- and cross-correlation) at quantized plateaus.
• Application to the quantum Hall bulk state at filling factor ν=2/3.

Main Results:

• Quantized plateaus can arise from distinct physical mechanisms, not solely edge mode transmission.
• Conductance measurements alone cannot distinguish between these mechanisms.
• Shot noise measurements can successfully discriminate between different mechanisms.
• Demonstrated scenarios for plateaus at G=e²/3h and G=e²/2h, and predicted a new plateau at G=5e²/9h.

Conclusions:

• The interpretation of quantized conductance plateaus requires careful consideration of underlying mechanisms.
• Shot noise analysis provides a powerful tool for characterizing quantum Hall states.
• New non-orthodox scenarios for conductance quantization are possible.