Entanglement in a molecular Lieb-lattice quantum computing circuit: A tensor network study

TL;DR

This study designs a molecular Lieb-lattice quantum circuit with spin-1/2 qubits, analyzing entanglement and phase transitions using tensor-network methods, providing insights for scalable molecule-based quantum computing.

Contribution

It introduces a novel molecular Lieb-lattice quantum circuit model and analyzes its entanglement properties and phase transitions with tensor-network techniques.

Findings

Rich entanglement patterns and quantum phase transitions identified.

Tunable spin coherence demonstrated under varying magnetic conditions.

Implications for molecular self-assembly quantum computing circuits.

Abstract

Here a finite-Lieb-lattice quantum computing circuit consisting of spin-1/2 quantum bits (qubits) and triplet couplers is designed. Important gradient - quantum entanglement - is analysed. This type of design could be realised in a vast range of molecules containing multiple radicals, in which the communications among qubits are controlled by the optically driven triplets. The von Neumann entanglement entropy, reduced density matrices, and spin-spin correlations were computed using tensor-network methods by varying the magnetic anisotropy and external magnetic field. This work uncovers the rich entanglement patterns, quantum phase transitions, and tunable spin coherence in this mixed spin system, designed for molecular spin-based quantum computing. These findings have important implications for triplet-mediated molecular self-assembly quantum computing circuit, especially for the entangling gate based on molecules. This work would provide a theoretical cornerstone for the experimental realisation of scalable molecule-based quantum computing circuits.