code: def Rotz(theta):
      r"""One-qubit rotation about the z axis.
  
      Args:
          theta (float): rotation angle
      Returns:
          array: unitary 2x2 rotation matrix :math:`e^{-i \sigma_z \theta/2}`
      """
      return qml.math.array(
          [
              [qml.math.exp(-0.5j * theta), 0.0],
              [0.0, qml.math.exp(0.5j * theta)],
          ],
          like=theta,
      )
  
imports: import pennylane
  from pennylane import numpy
  from pennylane import math
label_desc: Use image node_id 4 for calling a global function with example usage: Rotz(theta) and returns: qml