Minimizing buffer-induced nonlinearities and pump-induced resonances in dissipative cat qubits

Bosonic cat qubits can exhibit an exponential noise bias against bit-flip errors with increasing mean photon number. Here, we focus on cat qubits stabilized by two-photon dissipation (i.e., "dissipative cat qubits"), where pairs of photons are added and removed from a harmonic oscillator by an auxiliary, lossy buffer mode. In this talk, we discuss challenges associated with implementing two-photon dissipation. In particular we show how buffer-induced nonlinearities and pump-induced resonances can degrade the performance of dissipative cat qubits and present strategies for overcoming these challenges [Putterman et al., arXiv:2409.17556].