Chinese Optical Circuit Achieves Quantum Advantage Over Supercomputers
Researchers in China achieve quantum advantage by performing Gaussian boson sampling 100 trillion times faster than a supercomputer. The optical circuit uses squeezed light to solve complex mathematical problems that are practically impossible for conventional computers.
Researchers at the University of Science and Technology of China achieve a major milestone in quantum computing by performing a calculation 100 trillion times faster than a classical supercomputer. The team uses an optical circuit to execute a process called Gaussian boson sampling (GBS), which firmly demonstrates quantum advantage. While this specific computation primarily serves to prove that quantum systems outperform traditional machines, it also holds potential for specialized practical applications in the future.
Boson sampling works by sending single photons through a linear optical circuit filled with components like beam splitters. Because photons are bosons, two arriving at a beam splitter simultaneously take the exact same path, creating a complex interference pattern that is incredibly difficult for conventional computers to simulate. Calculating this output requires finding the "permanent" of a transformation matrix, a mathematical task that becomes overwhelmingly complex very quickly as more photons and output channels are added to the system.
To overcome the limitations of traditional boson sampling, the Chinese team employs single mode squeezed states of light instead of individual single photons. This GBS approach offers two crucial benefits over the standard method, starting with a significantly higher photon generation rate. Furthermore, Gaussian boson sampling calculates a similarly complex mathematical quantity that remains essentially impossible for even the most powerful supercomputers to process.