Magnon Seebeck effect

最近对磁性绝缘体中自旋Seebeck效应的观察表明，集体磁化激发，即自旋波及其量子磁子，在自旋-热量输运过程中起着至关重要的作用，并阐明了这一现象与传统热电产生的概念上的区别。我们项目的主要目标是揭示马尼翁·塞贝克效应背后的物理机制。其中最有趣和最重要的是将热流转化为磁性绝缘体中的自旋电压。为了了解热激活的磁振子流对这一过程的贡献，我们将用布里渊光散射谱的方法对温度梯度中磁振子气体的空间密度分布、时间和光谱特性进行全面的表征。我们将通过比较磁绝缘体中温度梯度产生的磁振子电流的数据与邻近顺磁金属中的电压测量来进一步研究自旋电压转换为电压的过程。最后，将开发控制热磁振子电流的方法，并优化自旋塞贝克效应电压的产生效率。

The recent observation of the spin Seebeck effect in a magnetic insulator demonstrates the crucial role of collective magnetization excitations, i.e. spin waves and their quanta, magnons, in spin-caloric transport processes, and illustrates the conceptual distinction between this phenomenon and conven-tional thermoelectric generation. The main goal of our project is to uncover the physical mechanisms underlying the Magnon Seebeck effect. The most interesting and important of these is the conversion of a heat flow into a spin voltage in a magnetic insulator. In order to understand the contribution of a thermally activated magnon current to this process, the spatial density distribution and the temporal and spectral characteristics of a magnon gas in a temperature gradient will be thoroughly characte-rized by means of Brillouin light scattering spectroscopy. We will further study the process by which a spin voltage is transformed into an electric voltage by comparing data on magnon currents generated by a temperature gradient in a magnetic insulator with electric voltage measurements in a contiguous paramagnetic metal. Finally, methods to control thermal magnon currents will be developed, and the efficiency of spin Seebeck effect voltage generation will be optimized.