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Coherent charge oscillations in a bilayer graphene double quantum dot
K Hecker1,2, L Banszerus3,4, A Schäpers3
1JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074, Aachen, Germany. Katrin.Hecker@rwth-aachen.de.
Nature Communications
|November 30, 2023
Summary
Researchers observed coherent charge oscillations in bilayer graphene quantum dots, a key step for understanding charge noise and developing qubits. This breakthrough opens new avenues for quantum computing research.
Area of Science:
- Quantum Mechanics
- Condensed Matter Physics
- Materials Science
Background:
- Landau-Zener-Stückelberg-Majorana (LZSM) interference is crucial for studying charge noise and decoherence in quantum dots (QDs).
- Bilayer graphene is a promising material for tunable QDs, potentially enabling spin and valley qubits.
- Coherent charge oscillations and charge noise in bilayer graphene QDs remain largely unexplored.
Purpose of the Study:
- To report the first observation of coherent charge oscillations in a bilayer graphene double QD.
- To measure charge decoherence times in this system using LZSM interference and photon-assisted tunneling.
- To establish bilayer graphene as a viable platform for investigating charge noise and quantum phenomena.
Main Methods:
- Utilized LZSM interference spectroscopy to probe coherent dynamics in the bilayer graphene QD.
- Employed photon-assisted tunneling as an independent method to measure charge decoherence times.
- Analyzed the observed coherent oscillations to characterize charge noise properties.
Main Results:
- Successfully observed coherent charge oscillations in the bilayer graphene double QD.
- Measured charge decoherence times averaging 400-500 picoseconds using both LZSM interference and photon-assisted tunneling.
- Demonstrated the capability of bilayer graphene QDs to host and study coherent charge dynamics.
Conclusions:
- The observation of charge coherence in bilayer graphene QDs is a significant advancement.
- This work validates LZSM interference and photon-assisted tunneling as effective techniques for characterizing charge noise in this system.
- Future experiments can now leverage these findings to investigate the origin and spectral distribution of charge noise in bilayer graphene, paving the way for improved qubit performance.
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