1. A memory device, comprising: a word line extending along a direction; a first electrode having a top side having a first width; a second electrode having a top side having a second width; 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 contacting the top sides of the first and second electrodes 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 thickness of the insulating member, wherein the bridge comprises memory material having at least two solid phases, and the bridge has a third width along the direction, the third width being less than the first width and less than the second width.