Quantum Integrated Circuits and Electrons Spins in Semiconductor Nanostructures

提出的量子信息和计算方案利用电子的单自旋或以双/三重量子点的形式具有更复杂的自旋织构。单量子点、双量子点和三重量子点可以作为量子信息方案中的量子比特，相邻量子线的电阻对附近的电子分布很敏感，因此可以作为自旋构型（如单重态、三重态和更一般的自旋态）的读出机制。这将允许量子比特和量子信息方案与电线中导致电子配对的强电子-电子相互作用并行开发。对温度、几何形状和影响自旋极化的因素等工作极限进行了研究和计算。例如，随着温度的升高或导线中载流子浓度的降低，自旋方向变得越来越不明确，达到非相干状态。该项目将涉及伦敦大学学院的复合设备制造和测量，并与总部位于剑桥的日立欧洲公司合作，日立欧洲公司对该项目感兴趣，并将为学生提供建议和安置。

Proposed schemes of quantum information and computation utilise the spin of the electron either singly or in the form of double/triple quantum dots with more complex spin textures. Single, Double and Triple Quantum Dots can act as qubits in quantum information schemes and the resistance of an adjacent quantum wire is sensitive to electron distribution nearby and so can act as a readout mechanism of the spin configuration such as singlet, triplet and a more general spin state. This will allow Qubits and a Quantum Information scheme to be developed in parallel with the strong electron-electron interaction in the wire which leads to electrons pairing. The operating limits such as temperature, geometry and factors affecting the spin polarization will be investigated and calculated. For example, as the temperature is raised, or the carrier concentration in the wire is lowered, the spin direction becomes increasingly ill-defined and the incoherent regime is reached. The project will involve compound device fabrication and measurements at UCL and collaboration with Hitachi Europe based in Cambridge which has an interest in the project and will provide advice as well as a Placement for the student.