The quanta of magnetic excitations – magnons – are known for their unique ability to undergo Bose‐Einstein condensation (BEC) at room temperature. This fascinating phenomenon manifests itself in the spontaneous formation of a coherent magnon state, if the density of magnons is increased above a critical value by an incoherent stimulus. For a long time, the only experimentally proven approach enabling the observation of roomtemperature magnon BEC was the injection of magnons using microwave pumping, which has significant drawbacks. Alternatively, the magnon gas can be driven into the BEC state using direct spin currents. This possibility was proposed theoretically more than a decade ago. However, its experimental implementation was reported only recently. In my presentation, I will briefly review the basic principles and major advances in the field of room‐temperature magnon BEC and then discuss in detail the formation of BEC induced by direct spin currents. I will show that this mechanism allows the efficient control of the thermodynamic characteristics of a magnon gas and can be used to create a stationary, spatially extended magnon condensate characterized by high temporal and spatial coherence. Additionally, this simple and robust driving method enables a large variety of exciting new experiments and paves the way for the implementation of integrated quantum magnonic devices.

 

via Zoom:

Meeting‐ID: 613 8714 4615
Kenncode: 020322