Lone Molecule Bridges Spin and Light ⚡ экспресс
For the first time, researchers have achieved stable coupling between a spin qubit (a quantum bit based on spin) in a single molecule and photons. The carbene molecule, embedded in a crystal, acts as an interface, combining bright fluorescence, high spectral stability (over an hour), and long spin lifetime (up to tens of milliseconds at 4.5 K). It’s like finding a needle in a haystack and making it sing a pure note. This result paves the way for quantum networks based on molecular systems, which are easier to manufacture than traditional solid-state defects.
Quantum networks need a mediator between storage — spin — and carrier — light. No single molecule had ever pulled off such a feat. But now physicists have found a solution. They placed a carbene molecule into a crystal and cooled it to -269°C. Using optical measurements, they saw that the molecule emits single photons for over an hour, and its spin — a magnetic property — preserves its state for tens of milliseconds. So the molecule became a bridge: one pillar in the world of light, the other in the world of matter.
Even though the molecule is ten thousand times thinner than a hair, it holds a quantum connection longer than many solid-state defects. Astoundingly, this bridge of carbon and hydrogen works more reliably than complex artificial crystals. And most importantly, such bridges can be chemically designed, like building blocks, tailored to any task. Chemical assembly is cheap and precise, unlike the laborious growth of crystals with defects. Perhaps they will become the foundation of the quantum internet.
🎯 A single carbene molecule — made only of [tag:carbon]carbon[/tag] and [tag:hydrogen]hydrogen[/tag] — is ten thousand times thinner than a hair, yet its spin stores a quantum state hundreds of times longer than many atomic defects.
🎬 The data exchange between molecule and light echoes sci-fi tales of quantum communicators.