Engineers at the University of Pennsylvania have built a chip that creates quantum skyrmions in pairs of entangled photons, and found that the pattern survives disturbances that destroy the entanglement itself. The results, published in Nature Physics, point to a sturdier way to carry quantum information.
What the Penn team built
According to Penn Engineering, the chip produces pairs of entangled photons and gives one photon a skyrmion pattern in its polarization. A skyrmion is a stable, swirling topological structure. The key result is that the pattern does not stay with just one photon: it transfers from that single photon to the shared state of the two-photon pair.
The skyrmion here is not a physical shape but a pattern in how light is polarized. “The light oscillates in different directions depending on where you inspect it,” said first author Haoqi Zhao, now a postdoctoral fellow at Yale. “It’s sort of like how regions of hair on your head grow in different directions.” Even when parts of the pattern are disturbed, its defining count of polarization states stays the same.
Why quantum skyrmions are robust
The team tested what happens when the photon pairs are disturbed, including by background light. The findings were striking:
- Under disturbance, the entanglement between the photons disappeared.
- The topological property, the skyrmion pattern, remained.
- The pattern broke only under stronger disruption.
- A quantum correlation called quantum discord persisted even after entanglement was lost.
“It’s as if one dancer’s unique movement suddenly became part of a duet, and persisted even when the dancers were separated,” said senior author Liang Feng, a professor in Materials Science and Engineering. “If we can learn to encode information in such resilient patterns, that could lay the groundwork for much more reliable quantum networks.”
How the quantum skyrmions chip was made
Penn Engineering said the work took nearly half a decade. The chip was fabricated in Penn’s Singh Center for Nanotechnology. “It’s a bit like building an entire factory in miniature,” said Yichi Zhang, a doctoral student and co-author. “One part of the chip generates entangled photons, another directs them where they need to go and still another creates the skyrmion pattern.”
Who was involved
Alongside Feng, Zhao and Zhang, the co-authors include:
- Shuang Wu and Yaoyang Ji of Penn.
- Isaac Nape and Andrew Forbes of the University of the Witwatersrand.
- Chenjie Zhang and Yijie Shen of Nanyang Technological University.
The research was supported by the Penn Engineering Futures Fund, QUIEST, the Gordon and Betty Moore Foundation and the National Science Foundation.
Why it matters for quantum technology
Quantum networks could one day connect quantum computers and enable new forms of secure communication, but Penn Engineering notes that quantum information is extraordinarily fragile and entanglement between photons is easily disrupted. The Penn results show a property of the photon pair, its topology, that holds up when entanglement does not. The team says the findings also shed light on the relationship between topology and quantum correlations beyond entanglement.
As a writer, I think the most interesting part is the idea that information can live in the shape of a shared state rather than in the delicate link itself. For more quantum stories, read about a diamond chip for quantum networks, the ESTIC 2026 quantum communication session, and the Andreev qubit supercurrent readout.
FAQ
What are quantum skyrmions?
They are stable, swirling topological patterns. In the Penn study, a skyrmion pattern in polarization was carried by the shared state of two entangled photons.
What did the Penn study find?
When the photons were disturbed, entanglement disappeared but the skyrmion pattern remained, breaking only under stronger disruption. Quantum discord also persisted.
Where was the quantum skyrmions research published?
In Nature Physics. The work was led by Liang Feng at the University of Pennsylvania, with first author Haoqi Zhao.