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Magnetic-Field-Dependent Equilibration of Fractional Quantum Hall Edge Modes
Tanmay Maiti1, Pooja Agarwal1, Suvankar Purkait1
1Saha Institute of Nuclear Physics, HBNI, 1/AF Bidhannagar, Kolkata 700064, India.
Physical Review Letters
|August 29, 2020
Summary
Researchers measured fractional conductance in a fractional quantum Hall (FQH) state. They observed new FQH plateaus and enhanced edge mode equilibration with increasing magnetic fields.
Area of Science:
- Condensed matter physics
- Quantum Hall effect phenomena
Background:
- Fractional quantum Hall (FQH) states are exotic states of matter occurring in 2D electron systems at low temperatures and high magnetic fields.
- Edge states in FQH systems exhibit unique transport properties that are sensitive to interactions and magnetic field strength.
Purpose of the Study:
- To investigate the behavior of fractional conductance in a ν=1 edge state.
- To explore the influence of magnetic field on the equilibration of fractional quantum Hall edge modes.
- To identify and characterize novel FQH plateaus.
Main Methods:
- Utilizing gate-tunable fractional quantum Hall liquids (1/3 or 2/3 filling) to partition a ν=1 edge state.
- Measuring fractional conductance for current injection and detection.
- Analyzing the magnetic field dependence of FQH plateaus and edge mode equilibration.
Main Results:
- Observation of two distinct sets of FQH plateaus: 1/9, 2/9, 4/9 at low magnetic fields and 1/6, 1/3, 2/3 at high magnetic fields.
- Experimental evidence for magnetic field-dependent equilibration of three FQH edge modes.
- A conductance of e²/3h was observed, attributed to edge reconstruction.
Conclusions:
- The observed FQH plateaus are explained by the magnetic field-dependent equilibration of edge modes.
- A significant enhancement in the equilibration lengths of FQH edge modes was found with increasing magnetic field.
- Edge reconstruction plays a crucial role in the observed conductance values.
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