A data storage medium includes a carrier substrate having an electrode layer on the surface thereof and a sensitive material layer extending along the electrode layeradapted to be locally modified between two electrical states by the action of a localized electric field. A reference plane extends globally parallel to the sensitive material layer and is configured to accommodate at least one element for application of an electrostatic field in combination with the electrode layer the electrode layer including a plurality of conductive portions having a dimension at most equal to 100 nm in at least one direction parallel to the reference plane and separated by at least one electrically insulative zone, where at least some of the conductive portions are electrically interconnected, the conductive portions defining data write/read locations within the sensitive material layer.