Chinese physicists have achieved quantum entanglement with 18 qubits, surpassing the previous world record of 10. This represents a step toward realizing large-scale quantum computing, according to a recent study published in the journal Physical Review Letters.
Quantum entanglement is a phenomenon in which two or more entangled subatomic particles, or qubits, can theoretically affect each other simultaneously regardless of distance. The idea was so counterintuitive that Albert Einstein mocked it as "spooky action at a distance."
However, this effect is extremely delicate and researchers have to overcome the effect of decoherence – the destruction of quantum states by outside interferences – if they wish to use this phenomenon for any applications.
Physicist Pan Jianwei, along with his colleagues from the University of Science and Technology of China, eastern China's Anhui Province, achieved the new record by simultaneously exploiting three different degrees of freedom-paths, polarization and orbital angular momentum of six photons, the fundamental particle of light.
The outcome combination resulted in a stable 18-qubit state. Full control over the number of entangled particles determines the fundamental ability for quantum information processing, according to the study.
The previous record holder was also Pan and his colleagues. His team achieved a stable 10-qubit entangle state back in 2017. Apart from the number of entangled particles, China also holds the world record of sending pairs of entangled photons over 1,200 kilometers, an achievement that could pave way for the global hack-proof Internet.