  We present a feasible protocol to mimic topological Weyl semimetal phase in a
small one-dimensional circuit-QED lattice. By modulating the photon hopping
rates and on-site photon frequencies in parametric spaces, we demonstrate that
the momentum space of this one-dimensional lattice model can be artificially
mapped to three dimensions accompanied by the emergence of topological Weyl
semimetal phase. Furthermore, via a lattice-based cavity input-output process,
we show that all the essential topological features of Weyl semimetal phase,
including the topological charge associated with each Weyl point and the open
Fermi arcs, can be unambiguously detected in a circuit with four dissipative
resonators by measuring the reflection spectra. These remarkable features may
open a new prospect in using well-controlled small quantum lattices to mimic
and study topological phases.
