THERMODYNAMIC EQUILIBRIUM OF ROTATING SUPERFLUIDS

The thermodynamic equilibrium of rotating liquid He II is investigated on the basis of the macroscopic Landau theory. After reviewing the classical theory of rotating fluids, it is shown that for He II the normal fluid component is in solid body rotation while the superfluid flow can be irrotational except for a set of vortex lines or vortex sheets which must be stationary in a reference frame rotating with the normal fluid. Therefore, an array of quantized vortex lines which rotate with the normal fluid can be considered to be in thermal equilibrium. The number and positions of the lines is determined by thermodynamic stability requirements. The dissipative effects must have the property that they vanish in equilibrium and that they drive the system to the state of equilibrium. It is further shown that the equations proposed by Khalatnikov fulfill these requirements. Copyright © 1969 by the American Institute of Physics.