Zero-Magnetic Field Fractional Quantum States.

Area of Science:

• Condensed Matter Physics
• Quantum Mechanics

Background:

• The fractional quantum Hall effect (FQHE) typically requires strong magnetic fields and Landau levels.
• Theoretical predictions of fractional conductance quantization without magnetic fields have remained unobserved.

Purpose of the Study:

• To demonstrate and manipulate fractional conductance quantization in the absence of Landau levels.
• To investigate the role of electron system relaxation and confinement asymmetry in forming new fractional states.

Main Methods:

• Utilized a low-density electron system in a GaAs-based one-dimensional (1D) quantum wire.
• Allowed the 1D system to relax in the second dimension, forming a zigzag electron array.
• Applied symmetric and asymmetric confinement potentials and an in-plane magnetic field.

Main Results:

• Observed both odd and even denominator fractional conductance quantization without a quantizing magnetic field.
• Enhanced the appearance of new fractional states by increasing confinement asymmetry.
• An in-plane magnetic field induced new even denominator fractions, suggesting electron pairing.

Conclusions:

• Electron relaxation in 1D quantum wires can lead to observable fractional states without magnetic fields.
• Confinement asymmetry and in-plane magnetic fields offer pathways to control and engineer these fractional states.
• These findings have significant implications for low-dimensional electron systems and the development of quantum technologies, including quantum computation.