Scientists at Kyoto University and Hiroshima University have achieved a breakthrough in quantum physics by successfully identifying the elusive W state of quantum entanglement, solving a 25-year-old challenge in the field[1].
The team developed a method to measure entangled W states using photonic quantum circuits, demonstrating it successfully with three photons. This achievement is significant because W states, along with GHZ states, are fundamental building blocks for quantum networks[1:1][2].
“More than 25 years after the initial proposal concerning the entangled measurement for GHZ states, we have finally obtained the entangled measurement for the W state as well,” said Shigeki Takeuchi, the study’s corresponding author[1:2].
The breakthrough enables single-shot identification of quantum states, eliminating the need for numerous measurements that grow exponentially with added photons. This advancement opens paths for:
- Quantum teleportation of information between distant locations
- New quantum communication protocols
- More efficient quantum computing methods
- Transfer of multi-photon quantum entangled states[1:3][3]
The research team used highly stable optical quantum circuits that could operate for extended periods without active control. They validated their method by successfully distinguishing different types of three-photon W states[3:1].
Yes, “quantum teleportation” just means transfering a quantum state from one location to another without knowing what that state is, in the same sense that you can copy a file from one place to another without knowing its contents. So it’s just a particular kind of information being transfered, not anything about how quickly it’s transfered. There is a lot of awful terminology in quantum mechanics.