Sigma Y Operator

The Y operator is another of the three Pauli matrices. Like the X operator, it is both Hermitian and unitary. This is also referred to as the y operator. On the Bloch sphere, it is the operator that rotates the qubit around the y-axis by an angle of π. The 2x2 matrix form of the σy operator is given as:

which is Hermitian as verified below: