基于多带超导体的超导-绝缘相变及量子同步研究

项目名称： 基于多带超导体的超导-绝缘相变及量子同步研究

项目编号： No.61271163

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 无线电电子学、电信技术

项目作者： 周世平

作者单位： 上海大学

项目金额： 76万元

中文摘要： 本项目主要研究基于多带超导体的超导-绝缘量子相变与量子同步问题。将建立描述多带超导如MgB2、YBa2Cu3O7、 铁基超导体的模型哈密顿形式表述；并由此推导对不同序的关联函数及其量子态时间演化方程(Bogliubov-de Gennes方程)和自洽迭代条件. 通过自洽叠代将模型哈密顿对角化. 研究在物理参量空间(如磁场、偏置电流、工作温度) 量子态演化过程. 深刻理解支配多带超导-超绝缘量子相变物理过程,揭示其输运规律. 探索实现量子态相位非局域量子同步的物理条件.将明确回答零能Majorana束缚态、分数量子磁通和涡旋-反涡旋基态存在性问题; 建议并论证基于零能本征束缚对态的量子比特及其量子态调控方案；为拓扑量子计算提供物理演示平台.

中文关键词： 多带超导；相互作用与宇称破缺；新奇量子态；相变与同步；Majorana 束缚态

英文摘要： This is a research proposal aimed to investigate the superconducting-insulating phase transition and quantum synchronization in multi-band superconductors, such as the magnesium-boron, the high Tc cuprate, and the iron-based superconductors. By diagonalization the Bogoliubov-de Gennes model Hamiltonian self-consistently, we will show that different orderings, in particular, the equal spin triplet and the spin-singlet correlations can coexist due to the intra- and inter-band coupling associated spin-split and spin-flip scatterings, and the spin-orbit interactions. Driven by external magnetic fields and the bias voltage/current, an electronic texture- superconducting domains with correlation wave functions of different orderings immersed into a weak-link matrix forms. The system can be described in terms of two characteristic energy scales, that is, the Josephson tunneling energy and the Coulomb blockade energy. While the system is expected to undergo a superconducting-insulating quantum phase transition by tuning the magnetic fields and the bias voltages, the phase boundary separating the superconducting and insulating phases is in need to be specified. More profound, in the vicinity of the transition, a stable domain structure forms when the synchronization of the phase of the pair correlations at the domains ac

英文关键词： Multiband superconductor；interaction and parity；novel quantum state；phase transition and quantum synchronization；edge mode and Majorana bound state