362
X. S. Wang and X. R. Wang
m
m
m
m
m
m
m
m
m
m
m
m
(a)
(b)
(c)
(d)
(e)
(f)
m
m
m
m
m
m
Fig. 14.2 Schematic diagrams of DW topology. The top panel illustrates three DWs. a–c are
representative diagrams for three DWs in R 1 → M 1 model, and d–f are in R 1 → M 2 model
write
read
Longitudinal recording
recording layer
read
write
recording layer
additional layer
Perpendicular recording
(b)
(a)
x
z
y
z
x
y
z
x
y
Fig. 14.3 a Three types of 180 ◦ DWs. From the top to the bottom: heat-to-head/tail-to-tail, updown Néel/down-up Néel, up-down Bloch/down-up Bloch. b Schematic diagrams of DW racetrack
memory: in-plane storage and perpendicular storage
X. S. Wang and X. R. Wang
m
m
m
m
m
m
m
m
m
m
m
m
(a)
(b)
(c)
(d)
(e)
(f)
m
m
m
m
m
m
Fig. 14.2 Schematic diagrams of DW topology. The top panel illustrates three DWs. a–c are
representative diagrams for three DWs in R 1 → M 1 model, and d–f are in R 1 → M 2 model
write
read
Longitudinal recording
recording layer
read
write
recording layer
additional layer
Perpendicular recording
(b)
(a)
x
z
y
z
x
y
z
x
y
Fig. 14.3 a Three types of 180 ◦ DWs. From the top to the bottom: heat-to-head/tail-to-tail, updown Néel/down-up Néel, up-down Bloch/down-up Bloch. b Schematic diagrams of DW racetrack
memory: in-plane storage and perpendicular storage