7 research outputs found
Enhanced steady-state coherence via repeated system-bath interactions
The appearance of steady-state coherence (SSC) from system-bath interaction
proves that quantum effects can appear without an external drive. Such SSC
could become a resource to demonstrate quantum advantage in the applications.
We predict the generation of SSC if the target system repeatedly interacts with
independent and non-correlated bath elements. To describe their behavior, we
use the collision model approach of system-bath interaction, where the system
interacts with one bath element (initially in an incoherent state) at a time,
asymptotically (in the fast-collision regime) mimicking a macroscopic Markovian
bath coupled to the target system. Therefore, the SSC qualitatively appears to
be the same as if the continuous Markovian bath would be used. We confirm that
the presence of composite system-bath interactions under the rotating-wave
approximation (RWA) is the necessary condition for the generation of SSC using
thermal resources in collision models. Remarkably, we show that SSC
substantially increases if the target system interacts collectively with more
than one bath element at a time. Already few bath elements collectively
interacting with the target system are sufficient to increase SSC at non-zero
temperatures at the cost of tolerable lowering the final state purity. From the
thermodynamic perspective, the SSC generation in our collision models is
inevitably linked to a non zero power input (and thus heat dissipated to the
bath) necessary to reach the steady-state, although such energetic cost can be
lower compared to cases relying on SSC non generating interactions.Comment: 21 pages, 6 figures. Updated references. We have extended previous
sections and added the thermodynamic cost for generating SS