Academics in Taiwan have unveiled the world's smallest quantum computer, capable of performing integer factorization using only a single photon. These significant strides in quantum technology were led by National Tsing Hua University's Department of Physics and Professor Chuu Chih-Sung from the Center for Quantum Technology Research. This breakthrough follows the completion of Taiwan's first quantum encryption network in 2023, which attracted interest from Chunghwa Telecom.
World's smallest quantum computer
During a press conference held by the University on October 16th, Professor Chuu's team showcased their photonic quantum computer. Its features include room-temperature operation, compact size, low cost, and compatibility with popular silicon photonics technologies. Wu Yu-Tong, a member of the research team led by TSMC Academician Douglas Yu, was also present to learn about the device's future developments.
"With Taiwan's semiconductor technology leading the world, techniques developed in Japan or the United States can no longer be used as references," Wu stated. "The photonic quantum computer presented by National Tsing Hua University marks a historical achievement, as it represents an unprecedented innovation."
Furthermore, he suggests that photons serve as excellent carriers, and there is hope to achieve miniaturization of quantum computers.
The results of the photonic quantum computer study have been published in Physical Review Applied. Chuu noted that photons are fundamental particles that transmit electromagnetic interactions, with a single photon possessing 32 dimensions of space, allowing for substantial information storage.
A unique approach
Currently, foreign-developed photonic quantum computers can utilize hundreds of photons; however, photons appear probabilistically. "One second it's there, the next second it disappears," says Chuu, explaining that this makes it challenging to control multiple photons appearing simultaneously.
As a solution, Chuu altered his approach by compressing all information into a single photon. The team's next goal is to continuously challenge and enhance the information storage capacity of a single photon, enabling it to hold more data and facilitate more complex quantum computations.
In contrast, the five-qubit superconducting quantum computer at Taiwan's Academia Sinica must operate at extremely low temperatures, resulting in high energy consumption and costs. Additionally, quantum states are easily disrupted by vibrations or electromagnetic fields, leading to information loss and computational errors. The photonic quantum computer overcomes these two major challenges.
Chuu pointed out that photons can maintain stable quantum states at room temperature without requiring extreme cooling environments, thus consuming less energy and being more cost-effective. Moreover, photons can be transmitted over long distances with minimal interference, providing unique advantages for commercial applications of quantum computers.
