Mitigating decoherence in Liouvillian non-Hermitian dynamics via controlled system-bath coupling

A paradigmatic setup for studying non-Hermitian quantum dynamics is composed of a single two-level system (TLS) coupled to a dissipative cavity bath. Usually, a fixed dissipation rate is introduced to the Lindblad dynamics of the TLS, with no further consideration of the bath. Depending on whether one performs post-selection of quantum jumps, the resulting non-Hermitian dynamics of the TLS is determined by a Hamiltonian or a Liouvillian superoperator. The latter inherently includes the decoherence effect, limiting the potential applications of Liouvillian non-Hermitian dynamics. In this presentation, I will talk about our recent work of revisiting this non-Hermitian setup by modeling the entire TLS-bath system. We demonstrate that an external drive to the TLS effectively controls its coupling to the bath and thus its dissipation rate. Then we revisit chiral state transfer via dynamically encircling Liouvillian exceptional points and demonstrate mitigated decoherence effects due to this mechanism. Our study opens new avenues to explore Liouvillian non-Hermitian dynamics in quantum applications.