Gate-voltage noise suppression in nanowire FerBo implementations

Determine whether gate-voltage–induced noise in semiconductor–superconductor nanowire implementations of the FerBo qubit can be sufficiently suppressed by filtering to enable robust, noise-protected operation.

Background

The proposed FerBo qubit replaces the fluxonium’s tunnel junction with a superconducting weak link, and semiconductor–superconductor nanowires are a natural platform for realizing highly transmissive junctions with gate tunability. However, the use of electrostatic gates introduces an additional noise channel associated with gate-voltage fluctuations, which can degrade coherence.

The authors note that careful filtering is required to mitigate this noise but explicitly acknowledge that it remains to be determined experimentally whether such mitigation is sufficient. Establishing this is central to the practical viability of the FerBo design.

References

For semiconductor-superconductor nanowire implementations, gate voltage tunability introduces an additional noise channel that requires careful filtering. Experimental investigation will determine whether this effect can be sufficiently suppressed.

— FerBo: a noise resilient qubit hybridizing Andreev and fluxonium states  (2604.01145 - Caceres et al., 1 Apr 2026) in Section 4 (Practical implementation)