Lifetime of excitations in atomic and molecular Bose-Einstein condensates

Recent experimental progress has produced Molecular Superfluids (MSF) in thermal equilibrium; this opens the door to a new class of experiments investigating associated thermodynamic and dynamical responses. We review theoretical picture phase diagram quasiparticle spectrum Atomic Superfluid (ASF) MSF phases. further compute parametric dependence lifetimes at one-loop order. In phase, $U(1)$ particle number symmetry breaks $\mathbb{Z}_2$ exhibits gapless Goldstone mode addition gapped $\mathbb{Z}_2$-protected atom-like mode. ASF completely, leaving behind an unprotected both phases, decays with rate given by celebrated Belyaev result, as single component condensate. is sharp up critical Cherenkov momentum beyond which it emits phonons. constant even small momenta. These decay rates govern spectral response microtrap tunneling lead features transmission atoms fired through molecular clouds.