Sample rotation is shown to induce frequency splittings in nuclear-quadrupole-resonance spectra. The splittings are interpreted both as a manifestation of Berry's phase, associated with an adiabatically changing Hamiltonian, and as a result of a fictitious magnetic field, associated with a rotating-frame transformation. Real and fictitious fields are contrasted. Related effects are predicted in other magnetic resonance experiments that involve sample rotation.

• Received 17 March 1987

DOI:https://doi.org/10.1103/PhysRevLett.58.2281