nt12dreuar3esd

216 | Nature | Vol 579 | 12 March 2020

Article

Inputa Inputb

Bias

a Current

DW

reservoir

DW

reservoir

Output

Input

a

Input

b

DW

reservoir

DW

reservoir

Output

f

Input a Input b

b Bias

Logic inputLogic output

abBias 0 (() Bias 1 (^)

1 (^)1 (^)0 (()0 (()

1 (^)0 (()1 (^)0 (()

0 (()1 (^)1 (^)0 (()

0 (()0 (()1 (^)1 (^)

NAND NOR

c

110

(^01)
10
0
1
01
0
1
0 0
0
0
1
1 μm
1 μm
1 μm
1
1
0
10
1
0
01
1
1
00
1
d
e
NAND (bias 0)
NOR (bias 1)
1 1
0
1 0
1
(^01)
1
0 0
1
(^00)
1
0 1
0
(^10)
0
(^11)
0
t
0
1
01
0
11
1
0 1
0
1 0
1
1
Initial Output
Input
a Inpu
tb
× 1 × 7 ×^11 ×^16 ×^19
Current pulses
Fig. 3 | Reconf igurable NAND/NOR logic gates. a, Coloured SEM image of a
reconfigurable NAND/NOR logic gate (right) and corresponding logic-circuit
(left). Red, blue and yellow colours indicate regions with OOP and IP magnetic
anisotropies and the Pt strip, respectively. b, Schematics showing the
relationship between the magnetization in the two logic inputs, the bias
and the logic output for the NAND gate. c, Truth table for the reconfigurable
NAND and NOR logic operations. d, e, MFM images of different logic
operations for inputs of ‘11’, ‘10’, ‘01’ and ‘00’ with a bias of ‘0’ (d) and ‘1’ (e) and
the corresponding logic-circuit diagrams. The DW reservoirs (circular pads at
the top of each image) and the bias are set to logical value ‘0’ (d) and ‘1’ (e) by
applying an OOP magnetic field of 1 kOe. f, MOKE image sequence and
corresponding schematics showing the operation of a single NAND gate
with a sequence of logic inputs driven by an electric current. The initial
magnetization is set to be ⊙ by applying an OOP magnetic field of 1 kOe. The
green and purple areas in the schematics correspond to ⊙ and ⊗
magnetization, respectively. The boundaries of the logic gate are indicated by
red dashed lines and the positions of the inverters are indicated by white solid
lines in the MOKE images. The direction and the number of current pulses
applied before each MOKE image are indicated (current density, 7.5 × 10^11  A m−2;
pulse length, 30 ns). The entire image sequence is shown in Supplementary
Video 5. The bright and dark areas in the device regions in d–f correspond
to ⊙ and ⊗ magnetization, respectively. All the scale bars are 1 μm.