According to Christopher Monroe: "Modular Ion Trap Quantum Networks: Going Big", the hyperfine states of the valence electron in the Yb+ is used as a qubit. I know that we can change the spin orientation of this electron by using precession by appropriately applying a magnetic field for a specific duration. However, he mentions that the qubit can be manipulated using lasers. I am unable to understand how this is done. Laser beam will only give a oscillating magnetic field right? How can this be used to create precession over any arbitrary axis (as required by Bloch Sphere rotations)?