Non-Markovian super-superradiance in a linear chain of up to 100 qubits

Abstract

We study non-Markovian enhancement effects in the spontaneous emission of a collective excitation in a linear chain of up to 100 qubits coupled to a one-dimensional waveguide. We find that for a critical separation of qubits, the system exhibits super-superradiant (SSR) behavior leading to collective decay stronger than the usual Dicke superradiance. Here time-delayed coherent quantum feedback effects are at play on top of the usual Dicke superradiance effects. We find a linear scaling for the SSR decay rate with increasing qubit number N such that Γ_{SSR}∼2.277Nγ_{0}, where γ_{0} is the single-emitter decay rate to a one-dimensional waveguide, as opposed to Γ_{Dicke}∼Nγ_{0} for Dicke superradiance. The SSR decay rate can be tuned with qubit separation distance and may therefore have application for quantum technologies.