Parity-Symmetry-Protected Multiphoton Bundle Emission

We demonstrate symmetry protected bundle emission in the cavity QED system under ultrastrong coupling regime. Parity of Rabi model only permits super-Rabi oscillations with periodic generation even photons cavity, which is realized by laser driven flip qubit and parity conserved transitions induced interaction. Combined dissipation, 2$n$-photon correlated emissions are allowed, corresponding purities significantly enhanced symmetry, due to almost perfect suppression odd photons. The switching between can be controlled manipulating an added magnetic field. This work extends multi-photon regime, offers prospect exploring symmetry-protected multi-quanta physics.