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S. Goolaup et al.
Table 1 NAND and AND Truth table formed based on the logic operations of the device showing
NAND and AND functionalities
corresponding to an output bit of “0” while that for the UHR remains unchanged as
a logic bit of “1”.
The logical output at the UHR and LHR for all the different input combinations
are summarized in the truth table in Table 1. For all the logic operations, the resulting
magnetic configuration of the UHR and LHR are complementary. For current flowing
from B to A through the metallic strip, the outputs at the LHR reveal a NAND logic
gate operation, while an AND logic gate operation is obtained at the UHR. The
striking feature of this device is that in a single clock cycle, two complementary
logic operations can be performed simultaneously.
2.5.2 NOT and COPY Boolean Logic Operations
Single Boolean logic bit operation was achieved by fixing Input 1 (vertical nanowire)
to logical bit “1” (magnetisation orientation along +y direction) and flowing current
from B to A through the metallic strip. When the structure was saturated along the −
x direction, which corresponds to the bit “0” in input 2, the DW propagation leads to
the switching of LHR, resulting in a logical “1” output as shown in Fig. 18. For logical
input bit “1”, the output at LHR reveals a logical bit “0” as presented in Fig. 18. The
output bit at the UHR always follows the input bit. The truth table formed in Table 2
shows the structure operates as logical NOT gate when the output is read at the LHR
while a COPY operation is obtained at the UHR in this configuration.
2.5.3 NOR and oR Boolean Logic Operations
By reversing the direction of the current flow through the metallic strip i.e. from A
to B, the polarity of the local Oersted field can be switched, as shown in Fig. 19. The
local Oersted field now attracts the DW with a positive charge but repels TDW with
a negative charge. From the NAND operation discussion, the magnetic gate has no
effect on the DW when the two input bits are the same, i.e. input 1 and input 2 are
S. Goolaup et al.
Table 1 NAND and AND Truth table formed based on the logic operations of the device showing
NAND and AND functionalities
corresponding to an output bit of “0” while that for the UHR remains unchanged as
a logic bit of “1”.
The logical output at the UHR and LHR for all the different input combinations
are summarized in the truth table in Table 1. For all the logic operations, the resulting
magnetic configuration of the UHR and LHR are complementary. For current flowing
from B to A through the metallic strip, the outputs at the LHR reveal a NAND logic
gate operation, while an AND logic gate operation is obtained at the UHR. The
striking feature of this device is that in a single clock cycle, two complementary
logic operations can be performed simultaneously.
2.5.2 NOT and COPY Boolean Logic Operations
Single Boolean logic bit operation was achieved by fixing Input 1 (vertical nanowire)
to logical bit “1” (magnetisation orientation along +y direction) and flowing current
from B to A through the metallic strip. When the structure was saturated along the −
x direction, which corresponds to the bit “0” in input 2, the DW propagation leads to
the switching of LHR, resulting in a logical “1” output as shown in Fig. 18. For logical
input bit “1”, the output at LHR reveals a logical bit “0” as presented in Fig. 18. The
output bit at the UHR always follows the input bit. The truth table formed in Table 2
shows the structure operates as logical NOT gate when the output is read at the LHR
while a COPY operation is obtained at the UHR in this configuration.
2.5.3 NOR and oR Boolean Logic Operations
By reversing the direction of the current flow through the metallic strip i.e. from A
to B, the polarity of the local Oersted field can be switched, as shown in Fig. 19. The
local Oersted field now attracts the DW with a positive charge but repels TDW with
a negative charge. From the NAND operation discussion, the magnetic gate has no
effect on the DW when the two input bits are the same, i.e. input 1 and input 2 are