Quantum computing offers the possibility of dramatically faster computations and solving problems that current computers can’t. But how does it work?

This new beginner’s guide walks would-be quantum programmers through implementing some quantum algorithms over the cloud on IBM’s publicly available 5-qubit IBMQX4 quantum computer. 

What is a Quantum Computer?

A quantum computer uses the principles of physics at the subatomic level to solve problems that current computers can’t. Its underlying architecture is similar to a conventional one—both contain chips, circuits, and logic gates that operate according to algorithms (a sequence of instructions)—but instead of transistors that switch on or off to symbolize ones and zeroes, quantum computers use particles like electrons or photons to encode information as qubits.

Qubits can exist in a state of both a 1 and a 0 simultaneously, called superposition, which enables them to perform multiple calculations at once. This parallelism is the foundation of a quantum computer’s power.

As a result, a quantum AI can solve complex optimization problems much faster than a conventional one. This can benefit industries and sectors such as pharmaceuticals, oil & gas, aerospace logistics, and financial portfolio management. The ability to quickly produce high-quality solutions could also help accelerate the drug development process and save companies significant money on R&D expenses.

How Does a Quantum Computer Work?

In contrast to the binary system around which conventional computers revolve, quantum computing uses qubits as the basic units of information. Qubits can be in a superposition of zero and one, allowing them to perform many calculations at once, much faster than traditional computers.

Quantum algorithms run on a set of rules that dictate the way the qubits interact with each other to compute an outcome. This interaction, called interference, allows a computer to amplify some outcomes while canceling out others. In the case of a quantum computer, this can solve problems that would be impractical to work out on a traditional computer.

What Applications Can a Quantum Computer Solve?

In the future, quantum computers could speed up chemistry calculations, crack encryption and improve machine learning. But the technology isn’t available today, and it may be a while before it can solve complex problems as quickly as conventional computers.

That’s because quantum computing can handle multiple complex calculations at once, whereas traditional computers perform one calculation at a time. Quantum computers also use entanglement, which allows two qubits to be in the same state simultaneously, even though they are separated by large distances. This spooky action at a distance is key to the power of quantum computers.

What is the Future of Quantum Computing?

With its quantum-enhanced processing speed, the future of quantum computing looks promising. In the short term, the technology will be used for advanced analytics, machine learning, AI, cryptography and Big Data searches. It will be applied to industries including aerospace design, utilities (nuclear fusion), pharmaceutical research and drug discovery, and polymer science.

The ability to process a vast amount of real-time data like weather patterns and traffic flow will be invaluable for the logistics industry. Optimal route planning will be easier and faster with the help of quantum computers.

In education, quantum computers will be capable of generating personalized learning programs. Teachers will be able to tailor curriculum to students’ individual skills and achievements.