Teleportation
One of the most important uses of entanglement is quantum teleportation. In teleportation, the state of one qubit is destroyed in one place and resurrected in another, accomplished by using …
Course: Understanding Quantum Computers
Photonic systems
In an earlier Step, we visited the laboratory of Professor Akira Furusawa at the University of Tokyo, and learned about using photons as qubits. In this video, we continue that …
Are Qubits just analog?
Qubits carry information in superposition and entangled states, which gives them capabilities that analog systems do not have. Analog classical data We can build computers using continuous variables, giving us …
The critical nature of isotopic engineering
Join us as Keio’s Professor Kohei Itoh explains how his team works to control the isotopic concentration in materials to help several research groups around the world improve the quality …
Multi-bit States
All of our important quantum algorithms will use more than one qubit. But before we get into using more than one qubit, let’s review how multi-bit states work in classical …
The DiVincenzo Criteria
Of course, our goal is to build and use a real quantum computer, not simply sit in our armchairs and hope one magically appears. So, how hard is it to …
Introduction of Week 2
This week, we move into the heart of quantum computing. The week is divided into four major Activities: Qubits, Entanglement, Basic Algorithm Idea, and State Variables. Threading through these Activities …
Atomic energy level
The simplest quantum system is the hydrogen atom, with a single proton for a nucleus and a single electron orbiting it. In an undergraduate quantum mechanics course, students are often …
An invitation to continue your learning
You have almost finished your first week on our course Understanding Quantum Computers – and we would like to invite you to continue your studies in quantum computing through The …
Nuclear Spin
An atom is composed of the atomic nucleus and the electrons in orbitals around it. Earlier, we saw how an electron can be used to create our quantum state variable. …
Recap of Week 1 and preview of Week 2
This brings us to the end of Week 1. We hope that you have a feel for why we are so excited about quantum computers, why we are “Wanting Quantum”. …
Charge and magnetic flux
In a superconductor, there is no electrical resistance. If you start an electrical current flowing, it will run forever. It can also maintain the state of individual quanta. In this …
Computation and Quantum Chemistry
Assistant Professor James Whitfield of Dartmouth College joins us to introduce the notion of quantum chemistry, and the kinds of problems we can solve. The accompanying text adds more context …
Electron spin
Electrons have a characteristic known as spin. Spin has a particular direction, and it creates a magnetic field; if a large number of electrons have their spins pointing in the …
Photons: our first state variable
Our first task in designing a quantum computer is to decide what kind of state variable we want to use. In this video, we visit the laboratory of Professor Akira …