Pure Spin Current in a Non-Equilibrium Magnetic Insulator 
                                                                                  
                                         
          
  
  
  
  
  
   
      
 
  
    
	 Non-equilibrium systems are found everywhere in nature and provide an array of interesting phenomena that are also essential for current- or heat-driven devices. Non-equilibrium systems are found everywhere in nature and provide an array of interesting phenomena that are also essential for current- or heat-driven devices.
- We investigate spin current in a magnetic insulator, YIG, under thermally drivenĀ  non-equilibrium conditions, a challenging task for conventional transport techniques
- Brillouin light scattering (BLS) is used to probe local phonon and magnon temperature and to map local magnon population
- Theoretically, we expand to the concept of magnon chemical potential to describe spin current in an non-equilibrium system
- We experimentally evaluate two mechanisms that drive spin currentĀ  in a magnetic insulator, temperature and magnon chemical potential gradient.