| Re: Non-equlibrium ( No.1 )|
- Date: 2016/11/18 18:30
- Name: Artem Pulkin
- I did not understand the second part of your question since, generally speaking, equilibrium has nothing to do with spin degree of freedom in particular. Otherwise this is what is supposed to be 'non-equilibrium':
1. The Non-Equilibrium Greens Function is a particular matrix describing the central region. It is hard for me to say why is it called 'non-equilibrium' but there is also an equilibrium Green's function describing bulk leads. Probably, people call it like that to emphasize the difference: there is a bulk and there is a surface/edge/scattering region. (I am not sure about these statements, though).
2. There may also be an applied bias driving system out of equilibrium. Ofc, when you apply a voltage your charge carriers and, thus, the charge density are supposed to move between the leads. This means that your (central region) charge density is out of equilibrium. However, it is a sort of a stationary state since, by fact, the charge density is constant in time and space.