Inequal Three Qubit Entanglement Using GHZ State Generation for Spin-Torque Based Qubit Architecture

Abstract

This article presents the generation of Greenberger-Horne-Zeilinger (GHZ) states using a spin-torque-based qubit architecture, introducing a hardware-native decomposition of the Hadamard and controlled NOT (CNOT) gates. Unlike optical or superconducting implementations, the proposed approach exploits intrinsic spin-transfer-torque dynamics to realize single-qubit and entangling operations with minimal external control. The method reduces gate overhead and decoherence, enabling high-fidelity (> 99%) GHZ formation. An unequal entanglement amplitude naturally arises from spin-torque non-linearities and is analytically characterized as a tunable property advantageous for quantum secret sharing (QSS) and asymmetric quantum communication schemes. Numerical simulations of state evolution and density-matrix fidelity validate the robustness and efficiency of the approach. The results demonstrate that current-driven spin-torque interactions provide a compact, energy-efficient platform for scalable multi-qubit entanglement, linking spintronic device physics with quantum information processing. © 2020 IEEE.