1. A memory device, comprising: a first electrode having a top side, a second electrode having a top side; an insulating member between the first electrode and the second electrode, the insulating member having a thickness between the first and second electrodes near the top side of the first electrode and the top side of the second electrode; and a bridge across the insulating member, the bridge having a first side and a second side and contacting the top sides of first and second electrodes on the first side, and defining an inter-electrode path between the first and second electrodes across the insulating member, the inter-electrode path having a path length defined by the width of the insulating member, wherein the bridge comprises memory material having at least two solid phases.