Tailoring the quantumness of a driven qubit

Abstract

We investigate the nonclassicality of a two-level system driven by an external time-dependent field in the presence of dephasing. We consider two criteria for nonclassicality, one based on the quantum witness built upon the no-signaling in time condition and one based on the temporal steering inequality, for a linearly driven qubit. We show that both strongly depend on the amplitude of the driving field. As a result, we demonstrate that the quantumness of the two-level system can be successfully controlled by properly tuning the driving strength. We establish in particular that maximal violations of classicality allowed by dephasing can be achieved at arbitrary chosen times.