Quantum computing is shaping up to be among the most transformative technologies of our era.
While still in their infancy, these powerful machines are expected to help us solve many problems by accelerating the speed at which we can process certain types of data by a factor of hundreds of millions.
But not all quantum computers are the same. Researchers are working on many different ways to apply principles of quantum mechanics to computing technology. This has led to a variety of methods, architectures and paradigms, all suited for different use cases or tasks.
So here I’ll overview some of the different categories, giving a brief explanation of what makes each one unique and what it’s hoped they will achieve.
First, What Is Quantum Computing?
Just in case you’re completely new to the topic – quantum computing refers to a new approach to computing that harnesses some of the strange and powerful properties of quantum mechanics, such as entanglement and superposition. Instead of using traditional “bits” (ones and zeros) like a classical computer, quantum computers use “qubits” that are spookily able to exist in more than one state simultaneously. This means they can potentially solve some very complex mathematical problems, such as those involving optimization problems or simulating complex real-world systems like molecular physics – far faster than existing computers.
So What Are The Different “Types” Of Quantum Computers?
Several distinct quantum computing methodologies have emerged, each leveraging quantum properties in different ways, making them suitable for carrying out different types of computation. Here’s an overview of some of the most popular:
Quantum Annealing
This is a quantum computing methodology that’s particularly well-suited to solving optimization problems. These are computations that require finding the best combination of a large number of variables. It can be of use in real-world scenarios ranging from planning the most efficient route for multi-drop delivery drivers to optimizing stock portfolios. D-Wave is recognized as a leader in this field of quantum computing and has worked with companies, including Volkswagen, to create systems that use annealing methodology to optimize assembly line packaging operations and delivery logistics.
Superconducting Quantum Computers
One of the most mature quantum computing methods involves building circuits from superconductive materials such as niobium or aluminum, cooled to near absolute zero temperatures. This allows qubits to exist in superposition states of both one and zero simultaneously, where they can be manipulated by microwaves. In simple terms, this lets them carry out computational logic operations (and/or/not etc) in a way that lets them explore multiple possible solutions to a problem in parallel, rather than one at a time. Superconductive quantum computing is being pioneered by companies such as IBM and Google and has real-world applications in drug discovery, artificial intelligence, and encryption.
Trapped Ion Quantum Computers
This involves using positively charged atoms (ions) trapped and held within a 3D space in a way that entirely isolates it from the outside world. This means that it can be held in its superposition state for a very long time rather than decohering into one or zero. Lasers are used to switch the ions between different states as required for calculations, as well as to retrieve the information that forms the “answer” to the question that needs to be solved. Leaders in this field of quantum computing include IonQ, which has worked with the United States Air Force to create secure quantum networking technology for communicating between drones and ground stations.
Photonic Quantum Computers
This involves harnessing photons, which are light waves, and manipulating them using optical components like beam splitters, lenses and mirrors. Having no mass, light waves are not affected by temperature. This means that photonic quantum computing doesn’t require super-low temperatures and a specially configured environment. Another benefit of being light beams is that the qubits encoded in photons can maintain their coherence over relatively long distances. Real-world applications for it have been found in quantum cryptography and communications, and leaders in the field include Xanadu.
Where Next For Quantum?
Although real-world use cases for quantum computing are increasing, much of the work in the field is still purely hypothetical, and various other methods are under development in labs and academic institutions.
Other research is focused on reducing the error rate of quantum computing caused by the delicate nature of qubits held in a quantum state.
It’s also worth noting that most quantum computing taking place today involves a hybrid model of quantum and classical methodologies.
As research and development continue, there’s no doubt we’ll start to see more breakthroughs in the journey towards practical, scalable and useful quantum computing.
