Tunneling through a coherent "Quantum antidot molecule"

Area of Science:

• Condensed Matter Physics
• Quantum Mechanics
• Mesoscopic Physics

Background:

• The fractional quantum Hall effect (FQHE) describes highly correlated electron systems in two dimensions under strong magnetic fields.
• Resonant tunneling phenomena are crucial for understanding electron transport in nanoscale devices.
• Quantum antidots offer a unique platform to study electron interactions and quantum interference effects.

Purpose of the Study:

• To investigate resonant tunneling through a quantum antidot within the fractional quantum Hall regime.
• To analyze the nature and coupling of resonant states involved in the tunneling process.
• To provide experimental evidence for coherent coupling between resonant states in such systems.

Main Methods:

• Experimental measurements of electrical conductance through a quantum antidot.
• Analysis of conductance peak envelopes to identify resonant states.
• Comparison of tunneling rates with phase breaking rates to assess coherence.

Main Results:

• Observed resonant tunneling through a quantum antidot in the FQHE regime.
• Identified tunneling via two distinct resonant states: one on the antidot, another on a disorder-induced potential hill.
• Determined that the coherent tunneling rate significantly exceeds the phase breaking rate.

Conclusions:

• The experimental results provide strong evidence for a coherently coupled "antidot molecule" system.
• Coherent tunneling between spatially separated resonant states is demonstrated.
• This work deepens the understanding of quantum interference and electron correlations in mesoscopic systems.