Deterministic generation of Gaussian pure state in quasi-local dissipative system

TL;DR

This paper demonstrates a method for deterministically generating any Gaussian pure state in a dissipative system with quasi-local interactions, using auxiliary systems and switching schemes, with robustness considerations.

Contribution

It introduces a practical approach for generating Gaussian pure states via quasi-local dissipative systems, including approximate Gaussian cluster states with simple auxiliary systems.

Findings

Deterministic generation of arbitrary Gaussian pure states is achievable.

A simple single-mode auxiliary system can generate approximate Gaussian cluster states.

The robustness of generated states against decoherence and parameter errors is analyzed.

Abstract

This paper shows that an arbitrary Gaussian pure state can be deterministically generated in a dissipative open system that has quasi-local interactions between the subsystems and couples to surrounding environment in a local manner. A quasi-local interaction, which means that the interaction occurs among only a few subsystems, is a crucial requirement for practical engineering of a dissipative system. The key idea is that, first, an auxiliary system having local interaction with environment is prepared, and then that auxiliary system is coupled to the underlying target system via a set of two-body Hamiltonians in such a way that a desired pure state is generated. Moreover, we show that, even with a simple single-mode auxiliary system, deterministic generation of an arbitrary approximate Gaussian cluster state is possible, by devising an appropriate switching scheme. Lastly, we discuss in a specific example how much a dissipation-induced pure Gaussian state can be perturbed by decoherence and parameter error.