Hello,

I have tried to solve this challenge

```
@qml.qnode(dev)
def two_close_spins_X(B, J, time, n):
"""Circuit for evolving the state of two electrons with an X coupling.
Args:
B (float): The strength of the field, assumed to point in the z direction.
J (float): The strength of the coupling between electrons.
time (float): The time we evolve the electron wavefunction for.
n (int): The number of steps in our Trotterization.
Returns:
array[complex]: The quantum state after evolution.
"""
e = 1.6e-19
m_e = 9.1e-31
alpha = B*e/(2*m_e)
hbar = 1e-34
beta = -J*hbar/4
##################
# YOUR CODE HERE #
##################
for i in range(n):
qml.RZ(-2*alpha*time/n,wires =0)
qml.RZ(-2*alpha*time/n,wires = 1)
qml.PauliRot(-beta*time/n, 'XX', wires = [0,1])
return qml.state()
```