NMR-like effect on Anisotropic Magnetic Moment of Surface Bound States in Topological Superfluid ³He-B

We present experimental observation of a new phenomenon, that we interpret as NMR-like effect on anisotropic magnetic moment of the surface Andreev bound states in topological superfluid $^3$He-B at zero temperature limit. We show that an anisotropic magnetic moment formed near the horizontal surface of a mechanical resonator due to symmetry violation of the superfluid $^3$He-B order parameter by the resonator's surface may lead to anomalous damping of the resonator motion in magnetic field. In difference to classical NMR technique, here NMR was excited using own harmonic motion of the mechanical resonator, and nuclear magnetic resonance was detected as a maximum in damping when resonator's angular frequency satisfied the Larmor resonance condition.