# Emerging unitary evolutions in dissipatively coupled systems

## TL;DR

This paper demonstrates that dissipatively coupled systems can be engineered to perform universal unitary operations, enabling quantum information processing through controlled dissipative processes in superconducting circuits.

## Contribution

It shows how to turn dissipative coupling into a resource for implementing arbitrary quantum gates, advancing quantum control methods.

## Key findings

- Dissipative processes can produce pure unitary dynamics under certain conditions.
- Engineered dissipation enables universal quantum control in superconducting circuits.
- Theoretical results are supported by detailed experimental feasibility analysis.

## Abstract

Having a broad range of methods available for implementing unitary operations is crucial for quantum information tasks. We study a dissipative process commonly used to describe dissipatively coupled systems and show that the process can lead to pure unitary dynamics on one part of a bipartite system, provided that the process is strong enough. If suitably engineered, the process allows to implement generic unitary operations. In fact, we show within the framework of quantum control theory that the dissipative process can turn the system of interest into a system capable of universal quantum information task. We characterize the time scales necessary to implement gates with high fidelity through the dissipative evolution. The considered dissipative evolution is of particular importance since it can be engineered in the laboratory in the realm of superconducting circuits. Based on a reservoir that is formed by a lossy microwave mode we present a detailed study of how our theoretical findings can be realized in an experimental setting.