cirq.XX

cirq.XX = cirq.XX

The X-parity gate, possibly raised to a power.

At exponent=1, this gate implements the following unitary:

X⊗X = [0 0 0 1]
      [0 0 1 0]
      [0 1 0 0]
      [1 0 0 0]
See also: cirq.MS (the Mølmer–Sørensen gate), which is implemented via
this class.