Section: New Results

Discrete-time reservoir engineering with entangled bath and stabilizing squeezed states

Participants: Z. Miao and A. Sarlette

The paper [15] is the first result of a line of work that we try to establish about the possible use of "time-structured reservoirs" towards stabilizing more complicated states of quantum systems. In particular, we here analyze a setting where reservoir items (qubits) are entangled over discrete time, and we show how it stabilizes squeezed states of a quantum harmonic oscillator. The parameters of the stabilized state can be tuned at will, in tradeoff with the convergence speed. The squeezing direction is determined by the phase of entanglement, thus allowing to distinguish genuine entanglement from mere classical correlations.

This work has allowed to identify the following lines for future research:

- first check time-varying, non-entangled reservoir inputs: from the same mathematical model, it appears that they can also stabilize squeezed states.

- provide a proof, on a non-trivial setting, of the specific benefit of entangled inputs: i.e. show how they achieve stabilization of some interesting states which are not accessible with any non-entangled inputs.

- laying the premises of possible approaches to studying continuous-time reservoir inputs which are entangled over time. This is currently an open question even from the modeling perspective.