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Published on: January 21, 2016
Tuning energy relaxation along quantum Hall channels
C Altimiras1, H le Sueur, U Gennser
1CNRS, Laboratoire de Photonique et de Nanostructures—Phynano Team, route de Nozay, 91460 Marcoussis, France.
Physical Review Letters
|January 15, 2011
Summary
Researchers controlled energy relaxation in quantum Hall edge channels, crucial for quantum information processing. Enhancing transmission to a contact boosted relaxation, while a closed loop froze it, revealing insights into inelastic mechanisms.
Area of Science:
- Condensed Matter Physics
- Quantum Information Science
Background:
- Chiral edge channels in the quantum Hall regime are ideal ballistic quantum channels.
- These channels hold potential for quantum information processing.
- Energy relaxation limits quantum coherence and the return to equilibrium.
Purpose of the Study:
- To experimentally demonstrate efficient tuning of energy relaxation in quantum Hall edge channels.
- To investigate the impact of transmission and channel geometry on energy relaxation.
- To elucidate inelastic mechanisms at filling factor ν(L)=2.
Main Methods:
- Experimental demonstration at filling factor ν(L)=2.
- Controlled enhancement of energy relaxation by increasing transmission to a floating Ohmic contact.
- Formation of a closed inner edge channel loop to study energy exchange.
Main Results:
- Energy relaxation is controllably enhanced by increasing transmission to a floating Ohmic contact, matching theoretical predictions.
- Forming a closed inner edge channel loop effectively freezes energy exchanges in the outer channel.
- Inelastic mechanisms within the outer edge channel at ν(L)=2 were found to be negligible.
Conclusions:
- Energy relaxation in quantum Hall edge channels can be efficiently tuned experimentally.
- Transmission to Ohmic contacts and channel geometry are key factors in controlling relaxation.
- The study provides crucial insights into the nature of inelastic mechanisms in these systems.
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