Quantum Dynamics of Magnetic and Electric Dipoles and Berry's Phase

We study the quantum dynamics of neutral particle that posseses a permanent magnetic and electric dipole moments in the presence of an electromagnetic field. The analysis of this dynamics demonstrates the appearance of a quantum phase that combines the Aharonov-Casher effect and the He-Mckellar-Wilkens effect. We demonstrate that this phase is a special case of the Berry's quantum phase. A series of field configurations where this phase would be found are presented. A generalized Casella-type effect is found in one these configurations. A physical scenario for the quantum phase in an interferometric experiment is proposed.