A Cooling Component for Quantum Computers

Today, quantum computers represent one of the greatest possible breakthroughs in data processing and problem solving. Unlike traditional computers which process information in a binary state (a bit is either represented by a “1” or a “0”), quantum computers operate using the principles of quantum mechanics and storing information in mind-bendingly complex qubits.

Unlike the traditional bit, a qubit can store information as a 1, a 0 or any other quantum superposition of those two states — simultaneously. By combining multiple qubits into a single system, engineers can begin to exponentially increase the computing power in a quantum system by using the idea of quantum entanglement, which is an idea Einstein panned as “spooky action at a distance,” to make massive correlations between the qubits in a system. These correlations will eventually create a quantum state that’s different from its original state based on the instructions issued to the machine during its computational process.

While the theory underpinning quantum computing is mind bending on its own (how do you observe a final result without changing it?), designing the hardware that will run these systems is equally challenging.

Think about it: just as quantum computing’s operations will be radically different from digital computing, so too will its hardware. In fact, there are numerous challenges still facing the field, such as how do you develop a transistor, a reprogrammable chip or other core components of a quantum computing system?

Well, a group of Finnish researchers working at Aalto University in Finland has made a breakthrough in quantum computing architecture, creating a “quantum circuit refrigerator” that can reduce errors in quantum computing processes.

In their original state, just before they’re set loose on a problem, qubits must be kept cool to ensure their delicate quantum state computes correctly.  But the process of keeping these bits cool hasn’t been simple.

According to an Aalto release, “Just like ordinary processors, a quantum computer also needs a cooling mechanism. In the future, thousands or even millions of logical qubits may be simultaneously used in computation, and in order to obtain the correct result, every qubit has to be reset in the beginning of the computation. If the qubits are too hot, they cannot be initialized because they are switching between different states too much.”

Using a two-nanometer thick insulators, the Aalto team excited a tunneling electron with slightly less energy than it would need for its usual tunneling behavior. To compensate and complete its usual course, the electron grabs a bit of energy from a nearby quantum device, in this case the qubit, cooling it down and keeping it suspended in the state needed to complete a calculation and state in order.

If all of this is a bit confusing, don’t be concerned. Even Richard Feynman opined that if you say you understand quantum mechanics, you’re lying. But to help out, here’s a video that further explains this breakthrough:

While initial tests of the Aalto quantum fridge used simulated qubits to confirm their design, the researchers are ready to move forward with the real thing. If their system works, quantum computing architecture may have just made a huge leap forward.