Spin Caloritronics

Fig. 1

We are applying the methods of theoretical physics to understand the properties of condensed matter structures on the nanoscale, motivated by scientific curiosity, new experimental discoveries and potential applications. The exponential increase of the figures of merits of information and communication technology in the past decades, referred to as Moore's Law, is believed to break down in the next decade due to excessive heat generation in nanoscale Si-based electronics. We contribute to this task by studying the quantum mechanics of transport properties in nanostructures. This will lead to better understanding of experiments on new materials, structures and devices made from semiconductors, metals, insulators, magnets, and superconductors. We strive to predict new physical phenomena and invent new concepts for devices, engines, and motors on the nanoscale with new functionalities in the hope that they will be discovered or fabricated in the future. Many of our activities are centered on the quantum mechanics of the spin degree of freedom of the electron. The science and technology of studying and controlling the coupled spin and charge current is called "spintronics".

Fig. 2
Only recently, it has been fully recognized that heat currents are strongly coupled to the spin as well, leading to a new field of "spin caloritronics" (Figure 1). Here we study, e.g., the spin Seebeck effect discovered by our experimental colleagues at the IMR. Another research activity is devoted to the coupling of the magnetic and mechanical degrees of freedom, such as nanoscopic versions of the Barnett (see Figure 2) and the Einstein-de Haas effects. We offer our students a competitive research environment with ample opportunities to interact with experimental groups at the IMR and elsewhere as well as with a large network of collaborating theoreticians around the world.