Scientists capture the state, unlocking quantum teleportation

Scientists have demonstrated the first tangled measure for W, a breakthrough for the transfer of quantum information and IT.

Quantum tangle highlights the deep fracture between classical physics and quantum physics. In this phenomenon, the state of each photon cannot be described independently, questioning the classic vision that each particle has its own distinct reality – an idea that has deeply disturbed Einstein. It is essential to grasp the importance of entanglement to advance quantum technologies of new generation.

To build such technologies, researchers must be able to reliably generate multiple tangled states and precisely determine what type of state has been produced. Conventional Quantum TomographyThe standard method to analyze these states faces a major obstacle: the number of measures required increases exponentially as the number of photons increases, creating a serious challenge for data collection.

Continue a tangled measurement for WT

When available, a tangled measurement Allows you to determine the type of tangled state in a single step. Such a measure had already been carried out for the Greenberger-Horne-Vellinger (GHz) Emature from the quantum state, but for the W state – another fundamental form of the multi -photon entanglement – it had not been theoretically proposed or demonstrated experimentally so far.

This challenge was taken up by a team of researchers from the University of Kyoto and the University of Hiroshima, who managed to develop a new tangled method of measurement capable of identifying the W state.

“More than 25 years after the initial proposal concerning the tangled measurement for the states of GHz, we finally obtained the tangled measurement for the W State, with a real experimental demonstration for the W to 3 photons”, explains the corresponding author Shigeki Takuchi.

The researchers based their approach on the symmetry of cyclic shift in the W state and introduced a theoretical method to build a tangled measurement using a quantum photonic circuit that performs quantum Fourier transformation For W of any photon number.

To validate the method, they built a device designed for three photons, using very stable optical circuits which could operate for long periods without active control. By sending three unique photons prepared with specific polarization states, the device has managed to distinguish different types of W à three photons states, each linked to a unique non -classic correlation between the entrance photons. The team also evaluated the loyalty of the tangled measurement, defined as the probability of obtaining the correct result when provided with a pure-state entry.

Future applications in quantum technologies

This achievement opens the door to Quantum teleportationor the transfer of quantum information. This could also lead to new quantum communication protocols, the transfer of states to a multi-photos quantum imprint and new measurement methods based on measurement quantum calculation.

“In order to accelerate the research and development of quantum technologies, it is crucial to deepen our understanding of basic concepts to offer innovative ideas,” explains Takeuchi.

In the future, the team aims to apply its method to a multi-photon quantum state on a larger scale and more general and plans to develop quantum photonic circuits on chip for tangled measures.

Reference: “Stopped measurement for W” by Geobae Park, Holger F. Hofmann, Ryo Okamoto and Shigeki Takeuchi, September 12, 2025, Scientific advances.
Two: 10.1126 / SCIADV.ADX4180

Financing: Japan Science and Technology Agency, Japan Society for the Promotion of Science

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