  The discovery that spin-orbit coupling can generate a new state of matter in
the form of quantum spin-Hall (QSH) insulators has brought topology to the
forefront of condensed matter physics. While QSH states from spin-orbit
coupling can be fully understood in terms of band theory, fascinating many-body
effects are expected if the state instead results from interaction-generated
symmetry breaking. In particular, topological defects of the corresponding
order parameter provide a route to exotic quantum phase transitions. Here, we
introduce a model in which the condensation of skyrmion defects in an
interaction-generated QSH insulator produces a superconducting (SC) phase.
Because vortex excitations of the latter carry a spin-$1/2$ degree of freedom
numbers, the SC order may be understood as emerging from a gapless spin liquid
normal state. The QSH-SC transition is an example of a deconfined quantum
critical point (DQCP), for which we provide an improved model with only a
single length scale that is accessible to large-scale quantum Monte Carlo
simulations.
