The quantum slalom
One of the biggest challenges facing STEM researchers today is the difficulty of building a fault-tolerant, stable quantum computer. In essence, modern physicists are darting back and forth between trying to scale quantum computers to functional sizes and attempting to squelch all the noisy errors as the systems grow. When it comes to qubits, the quantum equivalent of computer bits, bigger is usually better. But it’s also much noisier. The main reason for this is that it’s incredibly difficult to produce qubits reliably without relying on random states — this is called the probabilistic method for generating qubits. Essentially, scientists just sort of smash things around until the desired result emerges. The researchers at the Max Planck Institute for Quantum Optics took a different route. According to their paper:
Let’s dive in
Quantum computing relies on entanglement, that’s when two or more objects are prepared in such a way that anything that happens to one affects the other with total disregard for distance. Typically, photons (individual units of light) are entangled inside of a special kind of crystal. This results in a type of entanglement that’s relatively unpredictable. Scientists struggle to generate qubits effectively using this method because it’s probabilistic. The Max Planck team did away with the crystal creation chamber and instead turned a single atom into an entangled photon generator. Per a press release from the Max Planck Institutes: The team managed to beat the previous record of 12 entangled photons using this method and they reached generation levels of near 50%. In other words, they were able to generate stable entangled photons nearly half the time. This allowed them to perform longer, more accurate measurements on the photons themselves.
Eureka?
This could very well represent a ‘eureka moment’ on par with Google’s recent discovery of time crystals. According to the researchers, this technique for generating stable qubits could have massive implications for the entire field of quantum computing, but especially for scalability and noise-reduction: It’ll take some time to see how well this experimental generation of qubits translates into an actual computation device, but there’s plenty of reason to be optimistic. There are numerous different methods by which qubits can be made, and each lends to its own unique machine architecture. The upside here is that the scientists were able to generate their results with a single atom. This indicates that the technique would be useful outside of computing. If, for example, it could be developed into a two-atom system, it could lead to a novel method for secure quantum communication.
