Quasiparticle Andreev scattering in the ν = 1/3 fractional quantum Hall regime

Area of Science:

• Condensed Matter Physics
• Quantum Mechanics
• Mesoscopic Physics

Background:

• Exotic quasiparticles in the fractional quantum Hall regime possess tunable charges and statistics.
• Quantum point contacts (QPCs) serve as sources and analyzers for studying quasiparticle scattering.
• Standard scattering principles may not apply to these fractional quasiparticles.

Purpose of the Study:

• To investigate the scattering rules of exotic quasiparticles, particularly their deviation from electron behavior.
• To experimentally verify the predicted Andreev-like reflection mechanism for fractional quasiparticles.
• To explore the implications of unconventional quasiparticle behavior on quantum information processing.

Main Methods:

• Utilizing a quantum point contact (QPC) setup to generate and scatter quasiparticles.
• Employing shot noise and cross-correlation measurements to analyze electrical conduction.
• Independently determining the charge of transmitted and reflected quasiparticles.

Main Results:

• Observed Andreev-like reflection of an e/3 quasiparticle into a -2e/3 hole.
• Confirmed the simultaneous transmission of an e quasielectron.
• Demonstrated that electrical conduction does not conserve quasiparticle nature or number for dissimilar incident particles.
• Verified the coincidence of quasielectron and fractional hole through measurements.

Conclusions:

• The study confirms the existence of Andreev-like reflection for fractional quasiparticles, a mechanism distinct from standard elastic scattering.
• Experimental results advance the understanding of unconventional quasiparticle behavior in condensed matter systems.
• Findings suggest potential for generating novel quasi-particles/holes and enabling non-local entanglement for quantum technologies.