Researchers Tune Superconductivity in Twisted Bilayer Graphene

Dielectric environment controls pairing mechanism in moiré material

Apr. 12, 2026 at 5:06am

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A highly textured, abstract painting in earthy tones of green, brown, and blue, featuring sweeping geometric arcs, concentric circles, and precise spiraling forms, conceptually representing the intricate interplay of electronic interactions and dielectric screening that control superconductivity in twisted bilayer graphene.Dielectric engineering provides a new knob to tune the complex electronic interactions that govern superconductivity in twisted bilayer graphene.Columbus Today

Researchers have demonstrated that superconductivity in twisted bilayer graphene (tBLG) can be tuned and even switched off by engineering its dielectric environment. Their work reveals that the pairing mechanism in this moiré system is strongly controlled by electronic interactions that are highly sensitive to nearby materials, unlike in conventional phonon-mediated superconductors.

Why it matters

This discovery provides a new path toward designing superconducting materials and devices, as carefully chosen substrates and gate stacks can be used as an external control knob to stabilize or quench superconductivity. This could lead to the development of low-loss interconnects, adaptive quantum circuits, and more robust superconducting elements for quantum technologies.

The details

The researchers fabricated twisted bilayer graphene devices and positioned them a few nanometers above a strontium titanate (SrTiO₃) substrate, a synthetic perovskite with a very large, tunable dielectric constant. By increasing the dielectric constant in situ, they steadily suppressed the superconducting dome and, upon further tuning, extinguished superconductivity altogether. At larger twist angles, the SrTiO₃ environment enabled a superconducting 'pocket' even in regimes where correlated insulating states were absent.

  • The study was published on April 12, 2026.

The players

Ohio State University

A public research university located in Columbus, Ohio.

Imdea Nanoscience

A research institute focused on nanoscience and nanotechnology, located in Spain.

National Institute for Materials Science

A Japanese national research institute dedicated to materials science and engineering.

Chun Ning (Jeanie) Lau

A professor of physics at Ohio State University and co-author of the study.

Xueshi Gao

The lead author of the study.

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What they’re saying

“Electrons normally repel each other, but in superconductors they form pairs; this pair formation is the key to a superconductor's ability to conduct electricity without dissipation... Our evidence suggests that electrons themselves, depending on their sensitivity to their nearby environment, are unexpectedly important for material changes.”

— Chun Ning (Jeanie) Lau, Professor of Physics, Ohio State University

“If you could transmit electricity without energy loss, that would be hugely important for technologies used in our everyday life. Environmentally controlled superconductivity offers a new path toward this goal.”

— Chun Ning (Jeanie) Lau, Professor of Physics, Ohio State University

What’s next

The researchers plan to further investigate the microscopic mechanism behind the dielectric control of superconductivity in twisted bilayer graphene and explore the potential applications of this discovery.

The takeaway

This study demonstrates the power of engineering the dielectric environment to control the electronic properties of moiré materials like twisted bilayer graphene, opening up new possibilities for designing superconducting devices and advancing quantum technologies.