Tunable Flux Vortices in 2D Dirac Superconductors

The non-trivial geometry encoded in the Quantum Mechanical wavefunction has important consequences
for both non-interacting and interacting systems. Yet, our understanding of the relationship
between geometrical effects in non-interacting systems and their interacting counterparts is far from
complete. Here, we demonstrate how the single-particle Berry curvature associated with the normal
phase in two-dimensions modifies the fluxoid quantization of a Bardeen-Cooper-Schrieffer (BCS)
superconductor. Ideally, the magnetic flux enclosed inside a single vortex can be continuously
tuned between one and zero flux quantum. A discussion of the experimental scenarios where this
anomalous quantization is expected is provided. Our work demonstrates the importance of variational
ansatze in making a clear connection between the Berry phases of single-particle and many-body
wavefunctions.