  The quantum spin Hall edge is predicted to reliably produce Majorana zero
modes on the border between magnetic insulator- and superconductor-proximitized
regions of the edge. The direction of magnetization determines the size of the
induced magnetic gap and can control the resulting tunnel barrier. Here we
propose a way to avoid magnetic manipulations of the material and use
electric-only local control of the barrier. We follow with a design of a
charging-energy-protected qubit and a layout of a quantum computer based on the
quantum spin Hall effect. We estimate relevant scales and show that they allow
for testing of these ideas in the near future.
