Design of realistic switches for coupling superconducting solid-state qubits

Abstract

Superconducting flux qubits are a promising candidate for solid-state quantum computation. One of the reasons is that implementing a controlled coupling between the qubits appears to be relatively easy, if one uses tunable Josephson junctions. We evaluate possible coupling strengths and show, how much extra decoherence is induced by the subgap conductance of a tunable junction. In the light of these results, we evaluate several options of using intrinsically shunted junctions and show that based on available technology, Josephson field effect transistors and high-Tc junctions used as pi-shifters would be a good option, whereas the use of magnetic junctions as pi-shifters severely limits quantum coherence.

9 pages, 4 figures, submitted to Applied Physics Letters

References in corpus (3)

• Coherent Quantum Dynamics of a Superconducting Flux Qubit
• Decoherence and gate performance of coupled solid state qubits
• Quantum computation with un-tunable couplings

Cited by in corpus (7)

• Tunable Supercurrent Through Semiconductor Nanowires
• Fast two-bit operations in inductively coupled flux qubits
• Decoherence in a superconducting flux qubit with a pi-junction
• Stationary entanglement in strongly coupled qubits
• Interface steps in field effect devices
• A tunable coupler with ScS quantum point contact to mediate strong interaction between flux qubits
• Semiconductor Epitaxy in Superconducting Templates