Within the field of spintronics, devices based on the interaction between spin and heat flow have emerged as a potential candidate for new thermoelectric devices (devices which convert heat to electricity). “Magnons,” quanta of spin excitation waves, and their detection is key to further progress in this field.
NV centers in diamond have emerged as a key for high-resolution quantum sensors. It has been demonstrated that NV centers can detect coherent magnon. However, detecting the thermally excited magnons by heat using NV centers is difficult since the thermal magnons have much higher energy than the spin state of NV centers, limiting their interaction.
A team of researchers has successfully detected these energetic magnons in yttrium iron garnet (YIG), a magnetic insulator, by using a quantum sensor based on diamond with NV centers.
They used the interaction between coherent, low-energy magnons and NV centers as an indirect way to detect the thermally excited magnons. As it turns out, the current produced by thermal magnons modifies the low-energy magnons by exerting a torque on them, which can be picked up by the NV centers. (Phys.org)
The study has been published in Physical Review Applied.
