Preparation of two-qubit entangled states on a spin-1/2 Ising-Heisenberg diamond spin cluster by controlling the measurement

TL;DR

This paper presents a method to prepare specific entangled two-qubit states in a spin-1/2 diamond spin cluster by controlling measurement directions, with potential applications in quantum information processing.

Contribution

It introduces a novel approach to generate pure entangled states in a spin-1/2 diamond cluster through measurement control, enhancing state fidelity and entanglement.

Findings

Achieved conditions for preparing Bell states with high fidelity.

Demonstrated control of entanglement via measurement direction.

Provided a theoretical framework applicable to real diamond spin systems.

Abstract

The preparation of entangled quantum states is an inherent and indispensable step for the implementation of many quantum information algorithms. Depending on the physical system, there are different ways to control and measure them, which allow one to achieve the predefined quantum states. The diamond spin cluster is the system that can be applied for this purpose. Moreover, such a system appears in chemical compounds such as the natural mineral azurite, where the $Cu^{2+}$ are arranged in a spin-1/2 diamond chain. Herein, we propose the method of preparation of pure entangled states on the Ising-Heisenberg spin-1/2 diamond cluster. We suppose that the cluster consists of two central spins which are described by an anisotropic Heisenberg model and interact with the side spins via Ising interaction. Controlling the measurement direction of the side (central) spins allows us to achieve predefined pure quantum states of the central (side) spins. We show that this directly affects the entanglement and fidelity of the prepared states. For example, we obtain conditions and fidelities for preparations of the Bell states.