1. A memory device, comprising: a first electrode; a second electrode; a memory element between said first and said second electrodes, said memory element comprising: a chalcogenide glass layer comprising Sn x Se 100−x ; and a layer of metal-chalcogenide material between said chalcogenide glass layer and said second electrode, wherein said chalcogenide glass layer contains a conducting channel formed of Sn—Se bonds, and wherein said memory element has a first memory state and a second memory state, and said conducting channel is present in said chalcogenide glass layer in both said first memory state and said second memory state.