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JANUARY 2019    TAP TIMES          -4-             netic spin states in a multiferroic, a mate-
                                                                rial first created in 2001 by Ramamoorthy

                    New circuit (from 2)                        Ramesh, a UC Berkeley professor of mate-
                                                                rials science and engineering and of phys-
                                                                ics and a senior author of the paper.

        Dr. Sasikanth Manipatruni, who leads hard-
        ware development for the MESO project
        at Intel’s Components Research group in                 Changing the magnetic order
        Hillsboro, Oregon. MESO was invented by                 “The discovery was that there are mate-
        Intel scientists, and Manipatruni designed              rials where you can apply a voltage and
        the first MESO device.                                  change the magnetic order of the multifer-
                                                                roic,” said Ramesh, who is also a faculty
                                                                                     faculty scientist at Law-
                                                                                     rence Berkeley National

                                                                                     “But to me, ‘What would
                                                                                     we do with these mul-
                                                                                     tiferroics?’ was always
                                                                                     a big question. MESO
                                                                                     bridges that gap and
                                                                                     provides one pathway for
                                                                                     computing to evolve”

                                                                                     Reduced voltage
                                                                                     In the recently pub-
                                                                                     lished Nature paper, the
                                                                                     researchers report that
                                                                                     they have reduced the
                                                                                     voltage needed for mul-
                                                                                     tiferroic magneto-electric
                                                                                     switching from 3 volts to
        Single crystals of the multiferroic material bismuth-iron-oxide. The bismuth at-
        oms (blue) form a cubic lattice with oxygen atoms (yellow) at each face of the   500 millivolts, and predict
        cube  and  an  iron atom  (gray) near  the  center. The somewhat  off-center  iron   that it should be possible
        interacts with the oxygen to form an electric dipole (P), which is coupled to the
        magnetic spins of the atoms (M) so that flipping the dipole with an electric field   to reduce this to 100 mil-
        (E) also flips the magnetic moment. The collective magnetic spins of the atoms   livolts: one-fifth to one-
        in the material encode the binary bits 0 and 1, and allow for information storage   tenth that required by
        and logic operations.
                                                                                     CMOS transistors in use

        Transistor technology, invented 70 years
        ago, is used today in everything from cell-                                  Lower voltage means
        phones and appliances to cars and super-                                     lower energy use: the
        computers.                                                                   total energy to switch a
                                                                                     bit from 1 to 0 would be

        Transistors shuffle electrons around inside                                  one-tenth to one-thirtieth
        a semiconductor and store them as binary                   R. Ramesh         of the energy required by
        bits 0 and 1.  In the new MESO devices,                                      CMOS.
        the binary bits are the up-and-down mag-                                                           Page 6
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