C12, a French developer of carbon nanotube (CNT) based quantum electronics, has co-authored a study in Nature Communications demonstrating an electrically controlled metal–insulator transition in ultra-clean, suspended carbon nanotubes. The research showcases an energy gap that is tunable over nearly two orders of magnitude (200 μeV to 30 meV), validating C12’s “materials-first” strategy. By proving that high-purity nanotubes can exhibit predictable and controllable electronic behavior, the team has established a crucial foundation for building scalable, low-disorder spin-qubit architectures.
The experiment utilized a unique 15-gate “keyboard” architecture, where a 4-micrometer nanotube is suspended approximately 150 nm above a series of individually controlled palladium electrodes. By spatially modulating the local electrical potential—applying alternating voltages across the gates—the researchers induced a synthetic “charge density wave.” This mechanism mimics the Peierls transition found in complex condensed matter systems, effectively driving the nanotube from a metallic state to an insulating state. The study found that a minimum of seven modulated gates is required to develop a robust, clear energy gap, which remains stable against local perturbations.
Technical Significance for Quantum Scaling
- Low-Disorder Behavior: The “ultra-clean” growth process developed at C12 ensures that the electronic transport is dominated by the intentional electrostatic potential rather than random material defects. This is a prerequisite for reliable qubit addressing and high-fidelity gates.
- Decoherence Mitigation: Achieving a large, homogeneous energy gap is a natural way to extend decoherence countermeasures. The gap protects quantum states from low-energy uncontrolled excitations, providing a finite region of parameter space where qubits can operate safely.
- Topological Potential: The 15-gate setup serves as a precursor to engineering Su–Schrieffer–Heeger (SSH) or Kitaev-like chains. Such configurations are targeted for hosting Majorana modes and other non-abelian excitations, which could lead to topologically protected qubits.
By marrying advanced semiconductor manufacturing with frontier carbon science, C12 is positioning the carbon nanotube as a foundational material for the next generation of quantum processors. The ability to manipulate the low-energy spectrum at the nanoscale with such precision allows for the design of quantum devices that are unique at scale, reducing the control overhead typically required to “clean up” for material inconsistencies.
Read the full technical paper in Nature Communications here and explore C12’s vision for carbon-based quantum computing on LinkedIn here.
February 16, 2026
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