Magnetoelectric write and read operations in a stress-mediated multiferroic memory cell

Magnetic memory cells associated with the stress-mediated magnetoelectric effect promise extremely low bit-writing energies. Most investigations have focused on the process of writing information in memory cells, and very few on readout schemes. The usual assumption is that the readout will be achieved using magnetoresistive structures such as Giant Magneto-Resistive stacks or Magnetic Tunnel Junctions. Since the writing energy is very low in the magnetoelectric systems, the readout energy using magnetoresistive approaches becomes non negligible. Incidentally, the magneto-electric interaction itself contains the potentiality of the readout of the information encoded in the magnetic subsystem. In this letter, the principle of magnetoelectric readout of the information by an electric field in a composite multiferroic heterostructure is considered theoretically and demonstrated experimentally using $[ N × ( TbCo 2 / FeCo ) ]$/ $[ Pb ( Mg 1 / 3 Nb 2 / 3 ) O 3 ] ( 1 − x ) − [ PbTiO 3 ] x$ stress-mediated ME heterostructures.