Rotating the Qubit State

Probabilities of the rotated qubit state

We initialize our qubit with the state $|0\rangle$ (line 4). Then, we apply the $R_y$ gate on the qubit and pass as the first parameter the result of calling prob_to_angle with the probability value of 0.6 (line 13). The rest of the code remains unchanged.

In line 4, we initialize our qubit with the state $|0\rangle$. Then, we apply the $R_y$ gate on the qubit and pass as the first parameter the result of calling prob_to_angle with the probability value of 0.6 in line 13. The rest of the code remains unchanged.

As a result, we see a $60\%$ chance to measure the qubit as the value 1. We have found an effective way to control the probabilities of measuring 0 and 1, respectively.

Let’s see what happens if we apply the $R_y$ gate on a qubit in another state, for instance, in

$|+\rangle=\frac{|0\rangle+|1\rangle}{\sqrt{2}}$.