Programmable magnetic memory device

摘要

A memory device has an information plane ( 32 ) for storing data bits in a magnetic state of an electro-magnetic material at an array of bit locations ( 31 ). The device further has an array of electro-magnetic sensor elements ( 51 ) that are aligned with the bit locations. The information plane ( 32 ) is programmable or programmed via a separate writing device ( 21 ). The writing device provides at least one beam of radiation ( 26 ) for heating the electro-magnetic material at the bit locations to a programming temperature. The magnetic state of the bit locations is programmed by applying a magnetic field during said heating of selected bit locations via the beams of radiation. Hence the memory device provides a magnetic read-only memory (MROM) that cannot be (re-)programmed without the proper writing device.