[1] Nanomagnonics: Spin waves at the nanoscale

Spin waves, or magnons, are collective spin excitations in magnetic materials. Spin waves can propagate free of charge transport and therefore can indegenously avoid Joule heating induced energy dissipation. Owing to this fact, spin waves are promising for low-power consumption logic devices in the scope of beyond-CMOS computation. Spin waves with nanoscale wavelengths are particularly attractive for highly integrated nanomagnonic devices because the short-wavelength spin waves enter the exchange regime and can propagate with high velocities. However, the excitation and detection of short-wavelength spin waves are non-trivial. Our research group commit ourselves on the experimental investigation of spin waves at the nanoscale as well as their potential applications in nanomagnonic devices and circuits.

[2] Spin Caloritronics: Interplays of spin, charge and heat

Spin Caloritronics is an interdisciplinary research field between spintronics and thermoelectrics, which studies the interplays of spin, charge and heat. There are a great variety of interesting phenomena in this frame, such as the spin Seebeck effect, the thermal spin-transfer torque, the anomalous Nernst effect and so on. In our group, we study the thermal spin-transfer torque effect in metallic and also insulating systems, where the temperature gradient or heat current is found to be able to affect the magnetization dynamics of the ferromagnet and even the switching behaivor of the magnetization. Recently, our group have been working on investigating the anomalous Nernst effect on vaious material systems, such as magnetic Heusler thin films and antiferromagnet-based multilayers. The anomalous Nernst effect can be considered as a thermoelectric counterpart of the anomalous Hall effect, which may offer a solution for highly efficient on-chip thermal energy harvesting based on magnetic thin films.

[3] Experimental study of propagating spin waves

In recent years, emerging electronics, which focuses on electronic spins, spintronics has received extensive attention, including the 2007 Nobel Prize in Physics for its giant magnetoresistance effect due to its rapid application in high-density hard disk magnetic storage technology. Received a wide range of applications. However, for the giant magnetoresistance effect, electron transport is still used as a carrier for transmitting spin information. When modern electronic devices are gradually miniaturized or even nano-sized, the Joule heat generated by electron transport will increase exponentially, and the design of the device also poses a severe challenge. However, spin wave, as another physical mechanism for transmitting spin information, can transmit spin information only by the periodic variation of the phase of the electron spin precession in the space without electron transport. Propagating spin waves can replace spin-polarized currents as carriers for transmitting spin information. We plan to use microwave excitation and detection methods to conduct in-depth studies on propagating spin waves, including the propagation velocity of spin waves, wavelengths. , and physical properties such as attenuation distance.