code: def SingleExcitation(phi):
      r"""Single excitation rotation.
  
      Args:
          phi (float): rotation angle
  
      Returns:
          array: the two-qubit Givens rotation describing the single excitation operation
      """
  
      return math.array(
          [
              [1, 0, 0, 0],
              [0, math.cos(phi / 2), -math.sin(phi / 2), 0],
              [0, math.sin(phi / 2), math.cos(phi / 2), 0],
              [0, 0, 0, 1],
          ]
      )
  
imports: import pennylane
  from pennylane import numpy
  from pennylane import math
label_desc: Use image node_id 23 for calling a global function with example usage: SingleExcitation(phi) and returns: math