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Shot noise generated by graphene p-n junctions in the quantum Hall effect regime
N Kumada1,2, F D Parmentier2, H Hibino1
1NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi 243-0198, Japan.
Nature Communications
|September 5, 2015
Summary
Graphene p-n junctions act as electronic beam splitters, controlling Dirac Fermion transport. Noise studies reveal junction length impacts this behavior, with longer junctions showing reduced noise due to energy relaxation.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Electronics
Background:
- Graphene's unique electronic properties enable investigation of Dirac Fermion transport.
- Quantum Hall effect in magnetic fields influences electron and hole mode behavior at p-n junctions.
Purpose of the Study:
- To investigate the shot noise of mode mixing at graphene p-n junctions.
- To demonstrate the role of p-n junction length in electronic beam splitter behavior.
Main Methods:
- Shot noise measurements were performed on graphene p-n junctions.
- The influence of varying p-n junction lengths was analyzed.
Main Results:
- Short p-n junctions exhibit noise consistent with electronic beam splitter behavior.
- Longer p-n junctions show reduced noise amplitude due to energy relaxation.
- The observed energy relaxation length exceeds typical mesoscopic device sizes.
Conclusions:
- Graphene p-n junctions function as tunable electronic beam splitters.
- Energy relaxation significantly affects transport properties in longer junctions.
- Graphene's properties are promising for electron quantum optics and quantum information processing.
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