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Tunable Kondo physics in a carbon nanotube double quantum dot
S J Chorley1, M R Galpin, F W Jayatilaka
1Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom.
Physical Review Letters
|October 30, 2012
Summary
We studied a tunable two-impurity Kondo system in a carbon nanotube double quantum dot. Applying a magnetic field tunes the system from a local singlet state to a Kondo screened phase.
Area of Science:
- Quantum physics
- Condensed matter physics
- Nanotechnology
Background:
- Kondo physics describes the interaction between magnetic impurities and conduction electrons.
- Quantum dots offer tunable platforms for studying quantum phenomena.
Purpose of the Study:
- Investigate a tunable two-impurity Kondo system in a carbon nanotube double quantum dot.
- Explore charge regimes and the impact of interdot coupling and magnetic fields.
Main Methods:
- Fabrication and measurement of a carbon nanotube double quantum dot.
- Systematically varying experimental parameters like magnetic field and interdot coupling.
- Comparison with numerical renormalization group (NRG) calculations.
Main Results:
- The system approaches the two-impurity Kondo model in specific charge regimes.
- Zero magnetic field leads to a local singlet state due to interdot coupling disrupting Kondo physics.
- Application of a magnetic field enables tuning the system into a Kondo screened phase.
Conclusions:
- The carbon nanotube double quantum dot serves as a tunable platform for the two-impurity Kondo model.
- Magnetic fields are crucial for controlling the transition between different quantum phases.
- Experimental findings are consistent with theoretical predictions from numerical renormalization group studies.
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