Anyonic interferometry without anyons: How a flux qubit can read out a topological qubit

Abstract

Proposals to measure non-Abelian anyons in a superconductor by quantum interference of vortices suffer from the predominantly classical dynamics of the normal core of an Abrikosov vortex. We show how to avoid this obstruction using coreless Josephson vortices, for which the quantum dynamics has been demonstrated experimentally. The interferometer is a flux qubit in a Josephson junction circuit, which can nondestructively read out a topological qubit stored in a pair of anyons --- even though the Josephson vortices themselves are not anyons. The flux qubit does not couple to intra-vortex excitations, thereby removing the dominant restriction on the operating temperature of anyonic interferometry in superconductors.

7 pages, 3 figures; Added an Appendix on parity-protected single-qubit rotations; problem with Figure 3 corrected

References in corpus (9)

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Cited by in corpus (6)

• Interaction Effects in Topological Superconducting Wires Supporting Majorana Fermions
• Search for Majorana fermions in multiband semiconducting nanowires
• Majorana edge states in interacting one-dimensional systems
• Majorana End-States in Multi-band Microstructures with Rashba Spin-Orbit Coupling
• Interface Between Topological and Superconducting Qubits
• Topologically non-trivial superconductivity in spin-orbit coupled systems: Bulk phases and quantum phase transitions