Quantum information with Gaussian states

TL;DR

This paper reviews the fundamental properties, applications, and theoretical aspects of quantum Gaussian states, emphasizing their role in continuous variable quantum information processing and experimental robustness.

Contribution

It provides a comprehensive overview of Gaussian states in quantum information, covering properties, device applications, entanglement, and effects of experimental imperfections.

Findings

Gaussian states are robust and manipulatable with existing technology.

They enable quantum teleportation and cryptography with continuous variables.

The paper discusses quantum channel capacity and entanglement theory for Gaussian states.

Abstract

Quantum optical Gaussian states are a type of important robust quantum states which are manipulatable by the existing technologies. So far, most of the important quantum information experiments are done with such states, including bright Gaussian light and weak Gaussian light. Extending the existing results of quantum information with discrete quantum states to the case of continuous variable quantum states is an interesting theoretical job. The quantum Gaussian states play a central role in such a case. We review the properties and applications of Gaussian states in quantum information with emphasis on the fundamental concepts, the calculation techniques and the effects of imperfections of the real-life experimental setups. Topics here include the elementary properties of Gaussian states and relevant quantum information device, entanglement-based quantum tasks such as quantum teleportation, quantum cryptography with weak and strong Gaussian states and the quantum channel capacity, mathematical theory of quantum entanglement and state estimation for Gaussian states.