Chinese Researchers Synthesize Micrometer-Scale Single-Atom Metal Wires

A research team led by Li Kuo at the Center for High Pressure Science and Technology Advanced Research in Beijing has synthesized stable, carbon-encapsulated single-atom copper chains exceeding one micrometer in length, according to Chinese state media. Published in the journal Science, the study utilized high-pressure solid-state topochemical polymerization inside a Paris-Edinburgh press. The breakthrough links more than 4,000 copper atoms consecutively—extending previous international chain-length benchmarks by over two orders of magnitude—while demonstrating potential applicability to metals such as cobalt, nickel, and zinc.

Scaling single-atom metal wires to micrometer dimensions addresses a persistent structural challenge in low-dimensional materials research: atomic chains typically suffer from severe instability and breakage. By encasing continuous chains of over 4,000 atoms within protective carbon sheaths, the technique demonstrates that one-dimensional atomic conductors can achieve unprecedented aspect ratios, offering a tangible material platform for fundamental quantum physics studies and future nanoscale electronic interconnects.

A research group at the Center for High Pressure Science and Technology Advanced Research in Beijing has synthesized structurally stable, carbon-encapsulated single-metal-atom chains measuring over one micrometer in length, according to a report by Xinhua published in People's Daily. The findings, published in the academic journal Science, mark the first time single-atom-diameter metallic chains have reached micrometer-scale lengths. Single-metal-atom chains represent the thinnest possible one-dimensional metallic wires, with a cross-section measuring only a single atom across. While long considered ideal model systems for investigating low-dimensional quantum mechanics and one-dimensional transport phenomena, fabricating continuous, freestanding chains of significant length has historically been constrained by thermodynamic instability and spontaneous fragmentation. Led by researcher Li Kuo, the team overcame these limitations by applying high-pressure solid-state topochemical polymerization. Using a Paris-Edinburgh press, the researchers synthesized large-sized single crystals of carbon-coated copper atomic chains. After peeling individual chains from the crystal matrix, measurements confirmed that the single-atom copper wires exceeded one micrometer in length, linking more than 4,000 copper atoms in a continuous, unbroken chain. According to the research team, this dimensional threshold improves upon previously reported international preparation benchmarks for single-atom chains by more than two orders of magnitude. Scaled proportionally to macroscopic dimensions, the aspect ratio of the wire corresponds to an ordinary four-meter household copper cable drawn down to atomic thickness. Beyond copper, the researchers noted that the high-pressure synthetic route can be adapted to produce atomic chains from several other transition metals, including cobalt, nickel, and zinc. Mao Ho-kwang, a prominent high-pressure scientist and academician of the Chinese Academy of Sciences, remarked that atomic-scale ultrafine metal wires could provide entirely new material candidates for next-generation nano-circuits and flexible wearable electronics. He added that the work establishes a new technical pathway for the design and synthesis of low-dimensional functional materials.