Gauging the Kitaev chain

Understand

We gauge the fermion parity symmetry of the Kitaev chain.

• While the bulk of the model becomes an Ising chain of gauge-invariant spins in a tilted field, near the boundaries the global fermion parity symmetry survives gauging, leading to local gauge-invariant Majorana operators.
• In the absence of vortices, the Higgs phase exhibits fermionic symmetry-protected topological (SPT) order distinct from the Kitaev chain.
• Moreover, the deconfined phase can be stable even in the presence of vortices.