Entanglement between states of single quadrupole nuclear spin

TL;DR

This paper investigates how entanglement can be generated and detected in a single quadrupole nuclear spin system with spin 3/2, showing that magnetization can serve as an entanglement witness at very low temperatures.

Contribution

It demonstrates that a magnetic field can induce entanglement in a single nuclear spin system and that magnetization correlates with entanglement, enabling practical detection.

Findings

Entanglement achieved at ~5 mK in a single spin system.

Magnetization coincides with entanglement measures.

Magnetization can serve as an entanglement witness.

Abstract

We study entanglement between quantum states of multi level spin system of a single particle considering a nucleus with spin 3/2 in both the internal electric field gradient and the external magnetic field. It was shown that entanglement is achieved by applying a magnetic field to a single particle at low temperature (~ 5 mK). In this temperature range, the numerical calculation revealed the coincidence between magnetization and concurrence. As a result, the magnetization can be used as an entanglement witness for such systems.