Static flux bias of a flux qubit using persistent current trapping
arXiv:cond-mat/0608115 · doi:10.1088/0953-2048/19/11/011
Abstract
Qubits based on the magnetic flux degree of freedom require a flux bias, whose stability and precision strongly affect the qubit performance, up to a point of forbidding the qubit operation. Moreover, in the perspective of multiqubit systems, it must be possible to flux-bias each qubit independently, hence avoiding the traditional use of externally generated magnetic fields in favour of on-chip techniques that minimize cross-couplings. The solution discussed in this paper exploits a persistent current, trapped in a superconducting circuit integrated on chip that can be inductively coupled with an individual qubit. The circuit does not make use of resistive elements that can be detrimental for the qubit coherence. The trapping procedure allows to control and change stepwise the amount of stored current; after that, the circuit can be completely disconnected from the external sources. We show in a practical case how this works and how to drive the bias circuit at the required value.
arXiv comment5 figures submitted to Superconductor Science and Technology
References in corpus (8)
- Quantum state engineering with Josephson-junction devices
- Coherent Quantum Dynamics of a Superconducting Flux Qubit
- Superconducting Qubits: A Short Review
- Multiphoton transitions in a macroscopic quantum two-state system
- Flux Qubits and Readout Device with Two Independent Flux Lines
- Coherent control of a flux qubit by phase-shifted resonant microwave pulses
- Design of an RSFQ Control Circuit to Observe MQC on an rf-SQUID
- Tunable Flux Qubit manipulated by fast pulses: operating requirements, dissipation and decoherence