Disclaimer. While this text's goal is to help more people to be introduced to the fascinating world of Quantum Computing by providing an introductory insight, only the basis and some important resources to consult are covered. If the reader’s desire is to make real progress in the field, a deeper understanding is needed.
In recent years companies like Google and IBM have invested highly in quantum computing. In 2019, Google built the first machine that achieved quantum supremacy, that is the first to outperform a supercomputer. Then Jian-Wei Pan’s team at the University of Science and Technology of China has developed the world’s most powerful quantum computer, Jiuzhang, that can perform a task 100 trillion times faster than the world’s fastest supercomputer. Jiuzhang is reported to be 10 billion times faster than Google’s machine and to be able to perform calculations that a traditional computer would take 600 million years, in just 200 seconds.
However, even though the aforementioned billionaire computers seem unrealistic to many, if you are interested in having a first try in quantum computing with real quantum hardware now you can with Qiskit.
What is Qiskit?
Qiskit is an open-source framework that provides tools for implementing and manipulating quantum programs and running them on prototype quantum devices and also on simulators on a local computer.
The primary version of Qiskit uses the Python programming language and here you can find a textbook for learning how it works. Quantum computing is new and writing quantum algorithms can be very tricky, but Qiskit helps make it simpler and more visual.
The best way to learn is by doing. Qiskit allows users to run experiments on state-of-the-art quantum devices from the comfort of their homes. The textbook teaches not only theoretical quantum computing but the experimental quantum physics that realizes it.
To the untrained eye, a circuit built with IBM’s online Quantum Experience tool looks like something out of an introductory computer-science course. Logic gates, the building blocks of computation, are arrayed on a digital canvas, transforming inputs into outputs.
A quantum circuit, something called a Bell state (this is a quantum physics term to describe a set of entangled qubits or the Hello World in the quantum world for our purposes) and the gates modify not the usual binary 1 or 0 bits, but qubits, the fundamental unit of quantum computing. Unlike binary bits, qubits can exist as a ‘superposition’ of both 1 and 0, resolving one way or the other only when measured. Quantum computing also exploits properties such as entanglement, in which changing the state of one qubit also changes the state of another, even at a distance.
Those properties empower quantum computers to solve certain classes of problems more quickly than classical computers.
If you are an established user or a noob in Quantum Computing and Qiskit, there is plenty for everyone here to check and learn. There are plenty of ways to get started even if you are not a computer scientist, “I’m a Musician, and Here’s Why I’m Learning Quantum Computing”, and one popular way is with online courses.
Here are some other resources: