• Corpus ID: 247476148

Flux Qubit Based on Hybrid Ferromagnetic-Superconducting Device

@inproceedings{Rybakov2022FluxQB,
  title={Flux Qubit Based on Hybrid Ferromagnetic-Superconducting Device},
  author={Filipp N. Rybakov and Egor Babaev},
  year={2022}
}

• F. Rybakov, E. Babaev
• Published 16 March 2022
• Physics

One of the promising strategy to realize a quantum bit is based on creation of a superposition of circulating currents in a superconducting device [1, 2, 3, 4, 5, 6]. Such qubit realization, termed “flux qubit” is realized by creating a superconducting loop subject to external magnetic field (Fig. 1a). When the loop encloses (nearly) half of the superconducting flux quantum, Φ ≈ 12Φ0, there is an energy near degeneracy of clock-wise (CW) and counter-clockwise (CCW) circulation of superconducting currents which is exploited to create a quantum bit [1, 7, 8]. Some of the scalability issues are naturally related to necessety of creating stable external field in large area that also should be calibrated. Here we propose a realization of flux qubit without the external magnetic field that will provide a compact design. We propose biasing the device in a superconductor-ferromagnet hybrid realization where the flux bias is induced purely by vector potential from the ferromagnet component (Fig. 1b). First, we give analytical estimates for the idealized case, and then a self-consistent calculation for realistic material constants and geometries.