Exceptional-point-assisted entanglement, squeezing, and reset in a chain of three superconducting resonators

TL;DR

This paper demonstrates how exceptional points in a chain of superconducting resonators can be exploited for rapid quantum state transfer, entanglement distribution, and system reset, enhancing quantum control protocols.

Contribution

It introduces a scheme utilizing exceptional-point engineering in a lossy resonator chain for fast quantum-state synthesis and control, highlighting the role of EPs in multimode Gaussian systems.

Findings

Fast transfer of squeezing and entanglement achieved.

Reset infidelity below 10^-5 with specific waiting times.

Quasi-stabilization time scales as 1/(2√2 g).

Abstract

The interplay between coherent and dissipative dynamics required in various control protocols of quantum technology has motivated studies of open-system degeneracies, referred to as exceptional points (EPs). Here, we introduce a scheme for fast quantum-state synthesis using exceptional-point engineering in a lossy chain of three superconducting resonators. We theoretically find that the rich physics of EPs can be used to identify regions in the parameter space that favor a fast and quasi-stable transfer of squeezing and entanglement, or a fast reset of the system. For weakly interacting resonators with the coupling strength $g$, the obtained quasi-stabilization time scales are identified as $1/(2\sqrt{2}g)$, and reset infidelities below $10^{-5}$ are obtained with a waiting time of roughly $6/g$ in the case of weakly squeezed resonators. Our results shed light on the role of EPs in multimode Gaussian systems and pave the way for optimized distribution of squeezing and entanglement between different nodes of a photonic network using dissipation as a resource.