Creating cat states in one-dimensional quantum walks using delocalized initial states

TL;DR

This paper proposes a platform-independent method to generate macroscopic superposition states, known as cat states, in one-dimensional quantum walks using delocalized initial states, highlighting their formation mechanism and robustness.

Contribution

It introduces a novel approach to create cat states in quantum walks with delocalized initial states, emphasizing the role of the linear dispersion relation and robustness in photonic systems.

Findings

Cat states can be generated using delocalized initial states in quantum walks.

The linear dispersion relation is key to the formation of cat states.

The proposed states are robust against environmental interactions.

Abstract

Cat states are coherent quantum superpositions of macroscopically distinct states and are useful for understanding the boundary between the classical and the quantum world. Due to their macroscopic nature, cat states are difficult to prepare in physical systems. We propose a method to create cat states in one-dimensional quantum walks using delocalized initial states of the walker. Since the quantum walks can be performed on any quantum system, our proposal enables a platform-independent realization of the cat states. We further show that the linear dispersion relation of the effective quantum walk Hamiltonian, which governs the dynamics of the delocalized states, is responsible for the formation of the cat states. We analyze the robustness of these states against environmental interactions and present methods to control and manipulate the cat states in the photonic implementation of quantum walks.