  We investigate quantum phase transitions and quantum coherence in a quantum
compass chain under an alternating transverse magnetic field. The model can be
analytically solved by the Jordan-Wigner transformation and this solution shows
that it is equivalent to a two-component one-dimensional (1D) Fermi gas on a
lattice. We explore mutual effects of the staggered magnetic interaction and
multi-site interactions on the energy spectra and analyze the ground state
phase diagram. We use quantum coherence measures to identify the quantum phase
transitions. Our results show that $l_1$ norm of coherence fails to detect
faithfully the quantum critical points separating a gapped phase from a gapless
phase, which can be pinpointed exactly by relative entropy of coherence.
Jensen-Shannon divergence is somewhat obscure at exception points. We also
propose an experimental realization of such a 1D system using superconducting
quantum circuits.
