Analysis of Spin Polarized Transfer and of Micro-Macro Theories for Polymers and Liquid Crystals

调查员负责三个项目。 在第一个项目中，重点是分析和设计有效的数值方法来模拟最近提出的模型，当电流垂直于层平面时，多层膜中的磁化强度与自旋积累耦合的动力学。 自旋的动力学方程是具有间断系数的扩散方程，磁化动力学由铁磁性的Landau-Lifshitz方程描述。 在第二个项目中，研究者基于非均匀密度泛函理论研究了一种新的液晶模型。 该模型可以描述各向同性相、近晶相、近晶A相和晶相。最后，在第三个项目中，研究人员研究了聚合物混合物中聚集体的形成。 铁磁材料广泛应用于磁记录行业，该行业仍然是数字数据存储的主导技术。 该项目解决了一些技术难题，发现在磁性器件的设计，如磁存储器（MRAM）。 液晶有着广泛的应用。 它们的光学特性对电场和磁场高度敏感，这使得液晶成为光学开关器件的理想候选者，如视频显示器和光学存储器。 它们对温度变化也非常敏感，这使得它们在涉及传感器的应用中非常有用。 更普遍地说，聚合物出现在我们生活的大多数方面，从生物细胞内的羊水到日常使用的塑料和洗发水。了解生物膜的动力学和通过它们的转运对于开发有效的药物递送方法具有根本的重要性。 了解聚合物混合物中的聚集过程对新产品的设计具有重要影响。 这项研究的聚合物和液晶解决了一些这些技术和生物问题。

The investigator takes up three projects. In the firstproject, the emphasis is the analysis and the design of efficientnumerical methods for the simulation of recent models proposed forthe dynamics of the magnetization coupled to the spin accumulationin multilayers when a current perpendicular to the plane of thelayers is applied. The dynamical equation for the spin is adiffusion equation with discontinuous coefficients, and themagnetization dynamics is described by the Landau-Lifshitzequation from ferromagnetism. In the second project, theinvestigator studies a new model for liquid crystals based onInhomogeneous Density Functional Theory. The model can describethe isotropic, nematic, smectic A, and crystalline phases. Finally, in the third project, the investigator studies theformation of aggregates in polymer mixtures. Ferromagnetic materials are widely used in the magneticrecording industry, which continues to be the dominant technologyfor the storage of digital data. The project addresses some ofthe technological difficulties found in the design of magneticdevices such as magnetic memories (MRAMs). Liquid crystals have awide range of applications. Their optical properties are highlysensitive to electric and magnetic fields, which has made liquidcrystals ideal candidates for optical-switching devices, such asvideo displays and optical memories. They are very sensitive totemperature changes as well, which makes them useful inapplications involving sensors. More generally, polymers appearin most aspects of our life, from the amniotic fluid insidebiological cells, to plastics and shampoos used on a daily basis. Understanding the dynamics of biological membranes and transportthrough them is of fundamental importance in the development ofefficient methods for the delivery of medicines. Understandingthe process of aggregation in polymer mixtures can have asignificant impact in the design of new products. This study ofpolymers and liquid crystals addresses some of these technologicaland biological issues.