Set consecutive equal numbers in an array equal to zero

I have an array like

a = np.array( [ 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 0, 1] )

and am looking for a way to set consecutive equal elements to zero:

a_desired =  np.array( [ 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1] )

I've had a pretty unsuccessful time of it so far, I've tried something as simple as

for i in range(len(a)-1):
    if a[i+1] == a[i]:
        a[i+1] = 0 

with output [1 0 1 0 0 0 0 1 0 1 0 0 1], as well as adding more conditions, like

for i in range(len(a)-1):
    if a[i+1] == a[i]:
        a[i+1] = 0 
    if a[i+1] != a[i] and a[i] == 0 and a[i+1] != a[i]:
        a[i+1] = 0 

which has output [1 0 0 0 0 0 0 0 0 0 0 0 0], but I can't seem to be able to successfully capture all the conditions required to make this work.

Some help would be appreciated!