Quantum Logic with Prototype Molecular Spin-Qubits

该项目将专注于合成一个新的分子量子比特库，并通过配位化学将这些量子比特连接起来，组装原型两个和三个量子比特门。自旋量子位表现为与抗磁性过渡金属的配位复合物，该金属与氧化还原活性二硫杂环戊烯配体结合，该配体可以很容易地被化学或电化学氧化以产生不成对的自旋。氧化还原惰性的四膦配体将桥接两个金属二硫杂环戊烯单元，并且它们随后的氧化产生两个弱耦合的自旋-双退出系统。弱耦合是必不可少的，使得分子可以物理寻址以进入三重态。本项目首先制备了一系列具有不同金属离子、二硫杂环戊烯取代基和双膦桥结构的双金属配合物来调节电子耦合。先进的光谱表征和理论研究将确定双量子位门控的最佳组成。合成基序将被扩展以包含可切换的功能，其中可以在有限的时间段内生成未配对的自旋以创建各种自旋状态。开关将通过外部刺激，使用光，磁场或电力来访问。对这些原型两量子比特和三量子比特门的测试将有助于更深入地理解量子计算的基本要求。

This project will concentrate on synthesising a library of new molecular qubits and linking these through coordination chemistry to assemble prototype two- and three-qubit gates. The spin-qubit manifests as a coordination complex with a diamagnetic transition metal bound by a redox-active dithiolene ligand which can be readily oxidised chemically or electrochemically to generate unpaired spins. A redox-inert tetraphosphine ligand will bridge two metallodithiolene units, and their subsequent oxidation generates two weakly coupled spins - a two-quit system. The weak coupling is essential so that the molecule can be physically addressed to access the triplet state. The project begins with the preparation of a series of dimetallic complexes with different the metal ions, dithiolene substituents and diphosphine bridge structure to modulate the electronic coupling. Advanced spectroscopic characterisation and theoretical studies will define the optimal composition for two-qubit gating. The synthetic motif will be extended to incorporate switchable functionalities where unpaired spins can be generated for a finite period of time to create a variety of spin states. The switch will be accessed via an external stimulus, using light, magnetic fields, or electricity. Testing of these prototypical two- and three-qubit gates will facilitate a deeper understanding of the fundamental requirements for quantum computing.