Abstract: A Vuilleumier heat pump is disclosed in which hot and cold displacers are controlled by first and second electromagnetic actuators, respectively. The first actuator is capable of moving the hot displacer between the first and second ends of travel while the cold displacer remains stationary and the second actuator is capable of moving the cold displacer while the hot displacer remains stationary. Prior art crank arrangements are unable to provide dwell in one displacer while moving the other displacer. Actuation of the displacers according to embodiments of the present disclosure provides a higher coefficient of performance than crank arrangements.