According to one embodiment, a device includes a member including a first portion having a first dimension in first direction, a second portion spaced from the first portion and having a second dimension in the first direction, a third portion between the first and second portions and having a third dimension in the first direction, and a fourth portion between the first and third portions and having a fourth dimension in the first direction; and a circuit to supply a shift pulse including first and second pulses to the member and move a domain wall in the member. The third dimension is less than the first dimension. The second and fourth dimensions are less than the third dimension. A second value of the second pulse is less than a first value of the first pulse.