High-resolution magnetic resonance in superfluid 3He-B

The authors have measured small intrinsic shifts in the frequency for magnetic resonance in superfluid 3He-B in very homogeneous magnetic fields as a function of temperature above 0.5 mK at a pressure of 1.03 bar and frequencies of 3.87 and 5.82 MHz. These measurements provide the first direct experimental values of the dipole field energy which they find to be consistent with indirect methods based on interpretation of longitudinal magnetic resonance. The authors compare their results with predictions of the quasi-classical theory and the Ginzburg-Landau theory from which they deduce the Fermi liquid parameter F2a and the Ginzburg-Landau parameter β345