Tutorial 2 - manipulating qubit states using qutip

"QuTiP is open-source software for simulating the dynamics of open quantum systems."

Apr 20

In this session, I will teach you how to perform computations on a single qubit. A variety of quantum operations can be utilized to manipulate the states of a qubit. Precise manipulation of qubit states will allow one to perform calculations on quantum computers accurately. This precision combined with speed of computation (or gate operation) defines the clock speed of a quantum processor. This clock speed ultimately determines whether a given quantum computer is going to outperform its classical counterpart in completing certain tasks.

In this context, I will particularly discuss the Bloch sphere representation of a qubit. Bloch sphere is a geometric description of the state of qubits, and is named after the physicist Felix Bloch. Points on the Bloch sphere describe all possible states a qubit can acquire in the course of computation. Check out https://en.wikipedia.org/wiki/Bloch_sphere for more information on it.

We will use a popular quantum dynamics simulation toolkit called qutip to perform computations on a single qubit. I will demonstrate its basic functionalities that allows one to manipulate and subsequently plot the states of a qubit on the Bloch sphere (figure shown below).