2. Quantum Mechanics

While many resources focus mainly on the allure and almost futuristic nature of qubits, we need to understand that a working quantum computer is not made up of qubits alone. Qubits, indeed, are the showstopper, but a myriad of other layers are necessary to exploit the quantum phenomena that provide a quantum computer its extraordinary capabilities. In the following sections, we will navigate these layers, from the devices that bridge the chasm between the quantum chip and the classical control hardware, to the mathematical complexity of specific quantum algorithms. This interactive Jupyter book is divided into four parts, each delving into distinct aspects of qubits and their operations, the architecture, algorithms, and protocols of a quantum computer, and the quantum internet.

We will examine the building blocks of a quantum computer, and explore profound information about the qubits that form the core of a quantum computer and internet. Learn about the effective usage and control of qubits, and delve into the functioning of the most promising types of qubits currently under exploration:

  1. Silicon Spin Qubits: Leveraging the spin of an electron in a silicon environment.

  2. Diamond NV Center Qubits: Utilizing the unique properties of defects in diamond crystals.

  3. Superconducting Transmon Qubits: Employing superconducting circuits to create artificial atoms.

  4. Topological Qubits: Harnessing the properties of anyons in a topological quantum field.

  5. Photonic Qubits: Using the polarization or phase of a single photon.

  6. Trapped Ion Qubits: Exploiting the quantum states of ions trapped in an electromagnetic field.

  7. Quantum Annealing Qubits: Designed for solving optimization problems by exploring the energy landscape.

This interactive jupyterbook aims to offer a comprehensive understanding of the scientific principles behind a quantum computer and quantum internet, as well as a deep understanding of different types of qubits. We challenge you to fully grasp the working principles of these qubits, and by extension, the operational principles of a computer constructed from these qubits.

Our primary focus is to provide insight into these different types of qubits - the essential elements at the heart of a quantum computer and a quantum internet. We aspire to inspire each other and encourage you to bring your experiences, insights, and thoughts to the table via this interactive Jupyter book. The key message here is: don’t hesitate to share. We are all here to learn and grow together.

I’d like to once again take a moment to express my gratitude and acknowledge the invaluable contributions of Delft University, the University of Toronto, and edX. Their commitment to sharing and making cutting-edge technologies accessible to the world in such a comprehensive manner has been instrumental in my journey. Their world-class courses in the realm of Quantum Computing and Quantum Computer Technology have significantly deepened my understanding of these incredibly exciting yet tremendously complex subjects. I cannot recommend them enough for anyone eager to delve into the quantum realm.

Test Explanation

Explanation We can think of the repeater protocol as being divided into two smaller protocols. First, Alice and the repeater generate shared entanglement. Then, Bob and the repeater generate shared entanglement, which they use to teleport half of the Alice/repeater entangled state to Bob

  • It is not possible to read out a superposition of spin states.

  • Three quantum dots are required to perform this readout protocol.

  • Magnetic noise can prevent the spin-up electron to tunnel out, since the Lorentz force accelerates the electron perpendicular to the direction of motion.

  • A spin-down electron can acquire the energy necessary to tunnel out of the dot from thermal fluctuations.