“Quantum computing is the next big thing.” That’s what everyone has been saying. Huge names such as Google, Microsoft, NVIDIA, IDM and Intel are pouring money into superconductive quantum computing firms. According to PitchBook, quantum computing companies’ hardware and software have earned almost $1.02 billion from venture capitalists, just this year. So, let’s explore quantum computing, why you should care and why superconductive quantum computing is the most popular kind right now.
Imagine you have a classic computer. This is like having a really well-trained librarian who can only look at one book at a time to find an answer. It flips through the pages really fast, but it still has to go one by one.
Now, imagine you have a magical librarian. That’s your quantum computer. Instead of looking at books one at a time, this magical librarian can look at every book at once, like a giant, spooky library where all the books are open simultaneously.
In a classical computer, a bit is the basic unit of information and can only be in one of two states: 0 (off) or 1(on) like a light switch. However, when it comes to quantum computers, the basic unit of information is called a qubit. A qubit can be in a state of superposition, meaning that the qubit can represent both 0 and 1 at the same time, different to our classic bits. This ability to be in multiple states allows quantum computers to explore multiple possibilities at once.
Entanglement is another state in which qubits are connected to one another, even over vast distances such as entire lightyears apart. Measuring entangled qubits can tell you information about the qubit it is connected to.
Since quantum computers can make multiple decisions instantaneously, they are far faster than classical computers. This makes qubits useful for gigantic computing problems and it leaves classic computing useful for everyday tasks like web surfing. With quantum computers, we could crack complicated codes or run molecular simulations to create lifesaving medicines. Sounds useful, right? Wait until you hear about the rest.
There are six main types of quantum computing: superconductive, trapped ions, photonic, neutral atom, topological and quantum dots. The most common and promising type of quantum computing is superconductive quantum computing. That’s the one you need to know about.
So, why superconductive quantum computing?
This type of quantum computer is made from small superconducting electrical circuits, which are materials that, when ultra-cold (colder than outer space), have no electrical resistance. This is crucial because electrical resistance can cause energy loss, making it difficult to maintain the quantum effects that are central to quantum computing. Then, after we have no electrical resistance, quantum effects are stable, and the computer can successfully multitask.
Having stable quantum effects is incredibly important because they are what give the computer the ability to perform multiple calculations at once. Quantum effects such as superposition and entanglement are very fragile and can be easily broken down if there isn’t enough stability. That is why superconductive materials are so successful; it gets rid of disturbances such as heat or noise that would prevent quantum states lasting a long time.
The superconducting qubits that make up these computers are made from tiny loops of this ultra-cold superconducting material, which often use a Josephson junction, a tiny bridge for electricity that drives the real power of a superconductive quantum computer. On this bridge, paired electrons tunnel through a thin insulator—kind of like ghosts passing through walls.
Many companies are adding more qubits connected by Josephson junctions, making the computers more powerful than ever. And thanks to microwaves, we can control them. Think of a pendulum on a clock. A regular pendulum swings back and forth, like a classical computer going to 0 or 1. A Josephson junction is a pendulum in which—if we push it just right—it can be in two places at once. The microwaves are this push, pushing the pendulum to 0, 1 or both at once.
This is why superconductive quantum computers are the most popular, they are significantly quicker and can access this in-between state that classical computers cannot. In 2019, a quantum chip that Google made solved a problem faster than a supercomputer, proving how promising this field is. Still, quantum qubits are very fragile and can lose information easily, but that doesn’t take away from the fact that quantum computing is the future. With more research and work, quantum computers have the power to change technology forever. They already have. But that’s for next week, so please stay tuned for my article introducing the technological applications for superconductive quantum computing and what it can do for us.