Decoherence in a superconducting flux qubit with a pi-junction

作者:Kato T*; Golubov A A; Nakamura Y
来源:Physical Review B, 2007, 76(17): 172502.
DOI:10.1103/PhysRevB.76.172502

摘要

We consider the use of a pi junction for flux qubits to realize degenerate quantum levels without external magnetic field. On the basis of the Caldeira-Leggett model, we derive an effective spin-Boson model and study decoherence of this type of qubits. We estimate the dephasing time by using parameters from recent experiments of superconductor-insulator-ferromagnet-superconductor junctions and show that high critical current and large subgap resistance are required for the pi junction to realize a long coherent time.

  • 出版日期2007-11