Dynamical signatures of bound states in waveguide QED

Understand

We study the spontaneous decay of an impurity coupled to a linear array of bosonic cavities forming a single-band photonic waveguide.

• The average frequency of the emitted photon is different from the frequency for single-photon resonant scattering, which perfectly matches the bare frequency of the excited state of the impurity.
• We study how the energy of the excited state of the impurity influences the spatial profile of the emitted photon.
• The farther the energy is from the middle of the photonic band, the farther the wave packet is from the causal limit.