Future of Quantum Computers Unlocked by Ancient Stone

Researchers led by the University of St Andrews in Fife, Scotland, have made a breakthrough in the field of quantum computing through the utilization of a cuprous oxide gemstone mined in Nambia. Quantum computing has been dubbed the “holy grail” of science, but current quantum computers remain too small to outperform current standard computers.

The research, published in Nature Materials, was achieved through a partnership between scientists at Harvard University in Boston, United States, Macquarie University in Sydney, Australia and Aarhus University in Aarhus, Denmark.

The team used cuprous oxide (Cu2O) to create Rydberg polaritons. Rydberg polaritons continuously bounce back from light to matter and are crucial for the creation of quantum simulators, which are stored in quantum bits.

Quantum bits can use any value between 0 and 1, while binary bits, used in classical computers, can only be 0 or 1, allowing quantum bits to store far more information and perform several processes simultaneously.

The project’s lead, Dr. Hamid Ohadi of the School of Physics and Astronomy at the University of St Andrews, said of their research, "Making a quantum simulator with light is the holy grail of science. We have taken a huge leap towards this by creating Rydberg polaritons, the key ingredient of it."

The belief is that quantum computing will allow scientists to solve increasingly complex problems in a fraction of the time.

To create Rydberg polaritons, the team of researchers used two highly reflective mirrors to trap light. Then they inserted the cuprous oxide crystal, thinned and polished it into a 30-micrometer thick slab, and placed it between the two mirrors. The results were Rydberg polaritons 100 times larger than ever displayed before.

According to Dr. Sai Kiran Rajendran, one of the leading authors of the study, purchasing the cuprous oxide crystal was the easy part.

"Purchasing the stone on eBay was easy. The challenge was to make Rydberg polaritons that exist in an extremely narrow color range."