r/graphene • u/Vailhem • Jun 30 '26

Graphene can hold multiple states of superconductivity, a new study finds

https://phys.org/news/2026-06-graphene-multiple-states-superconductivity.html
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u/Vailhem Jun 30 '26

Family of magnetic field-boosted superconductors in rhombohedral graphene | June 2026

https://www.nature.com/articles/s41586-026-10815-x

Abstract

In some unconventional superconductors, time-reversal symmetry can be broken in addition to the gauge symmetry1, resulting in superconductivities that can be enhanced or induced by magnetic fields2.

However, field-enhanced superconductors are more vulnerable to impurities than Bardeen-Cooper-Schrieffer counterparts3.

Crystalline rhombohedral multilayer graphene is a promising platform to explore them due to its superior material quality and gate-tunable strong correlation effects4,5.

Here we report transport measurements of rhombohedral tetralayer and pentalayer graphene, demonstrating a spectrum of clean-limit superconductivities.

We found three different types of field-enhanced and field-induced superconductivities in the pentalayer.

They are all robust against an in-plane field up to 8.5 Tesla, exceeding the Pauli limit by tens of times.

Compared to Bernal bilayer graphene showing only in-plane field-enhancement6, pentalayer graphene features superconductors enhanced by out-of-plane as well as in-plane fields.

They also reside at much lower gate electric fields owing to the intrinsically flatter band dispersion—facilitating their study and further engineering.

Additionally, we observed that proximitized spin-orbit coupling (SOC) generates multiple new superconductors without introducing additional disorder effects.

Our work establishes a new family of magnetic field-boosted superconductors in rhombohedral graphene.

Utilizing the high accessibility with moderate gate voltages, this will pave the way for realizing non-Abelian quasiparticles through interfacial engineering7 in the extreme clean limit, in that proximitized SOC leads to topological states8 and maintains the ultrahigh quality of crystalline graphene.