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Charging effects in the inductively shunted Josephson junction
Jens Koch1, V Manucharyan, M H Devoret
1Department of Physics, Yale University, New Haven, Connecticut 06520, USA.
Physical Review Letters
|April 7, 2010
Summary
Choosing an inductive shunt for Josephson junctions allows for observable charging effects. This resolves a paradox, showing inductive and capacitive shunts behave similarly at high frequencies for large inductances.
Area of Science:
- Quantum electronics
- Solid-state physics
Background:
- Josephson junctions are crucial in quantum electronics.
- The shunting impedance affects charge transfer quantization.
- A discrepancy arises between capacitive and inductive shunts for large inductances.
Purpose of the Study:
- To resolve the paradox between capacitive and inductive shunting of Josephson junctions.
- To investigate the behavior of shunted Josephson junctions in the limit of large inductances.
- To explore the potential for observing charging effects with inductive shunts.
Main Methods:
- Theoretical analysis of Josephson junction circuits.
- Comparison of energy spectra for capacitive and inductive shunts.
- Analysis of high-frequency responses in the large inductance limit.
Main Results:
- Energy spectra differ significantly between capacitive and inductive shunts.
- High-frequency responses become identical for both shunts when inductance (L) is large.
- Inductive shunting avoids charge noise, enabling clearer observation of charging effects.
Conclusions:
- The paradox in Josephson junction shunting is resolved for large inductances.
- Inductive shunting offers a viable path to observe quantum charging effects.
- High-frequency response unification suggests a common underlying physics at large L.
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