Spin Seebeck mechanical force

Electric current has been used to send electricity to far distant places. On the other hand, spin current, a flow of electron spin, can in principle also send angular momentum to distant places. In a magnet, there is a universal spin carrier called a spin wave, a wave-type excitation of magnetization. Since spin waves exhibit a long propagation length, it should be able to send angular momentum that can generate torque and force at a distant place: a new function of magnets. Here we observe mechanical angular momentum transmission and force generation due to spin waves injected into Y 3 Fe 5 O 12 by the spin-Seebeck effect. The spin-wave current, transmitted through a Y 3 Fe 5 O 12 micro cantilever, was found to create a mechanical force on the cantilever as a non-local reaction of the spin-Seebeck effect. Spin-wave current can be generated remotely even in open circuits, and it can be used to drive micro mechanical devices. Spin current carrying angular momentum enables intriguing phenomena and many fascinating applications. Here the authors demonstrate that thermally driven spin Seebeck current can give rise to the mechanical torque when transmitting through a Y 3 Fe 5 O 12 micro cantilever.