Can Fluctuation-Dissipation Theorem Apply to Magnetic Forces

[Spin Operator]

Let's say I have multiple spin systems (atoms in a protein) in a solution of water and the spin systems are all producing a magnetic field [tex] \mathrm{B_{loc}} [/tex] that affects nearby spin systems.
Will the fluctuation-dispersion theorem apply to the force generated by a spin's magnetic field [tex] Force_{B_{local}} [/tex]? I know it applies to the force R generated by collisions between the spins and water using the Langeval equation but what about the force between spins?

 

[eljose79]

Yes, the fluctuation-dispersion theorem can apply to the force generated by a spin's magnetic field, also known as the dipole-dipole interaction. This force is a result of the interaction between the magnetic moments of the spins and can be described by the Langevin equation. The fluctuation-dispersion theorem states that the average force between two particles is related to the fluctuation in their positions and velocities. In this case, the fluctuation in the positions and velocities of the spins in the solution will contribute to the force between them. Therefore, the fluctuation-dispersion theorem is applicable to the dipole-dipole interaction between spins in a solution of water.