How Perovskites and Twisted Graphene Are Redefining High-Temperature Superconductivity
The quest for effortless energy is closer than we think.
Imagine a world where electricity travels from power plants to your home without any loss, where medical MRI machines become dramatically cheaper to operate, and high-speed levitating trains are the norm. This isn't science fiction—it's the future promised by high-temperature superconductors, materials that can conduct electricity with perfect efficiency without requiring extreme cold. For decades, a class of materials called perovskites held the key to this revolution. Now, groundbreaking experiments with twisted graphene are opening even more astonishing possibilities, revealing quantum phenomena we're only beginning to understand.
Superconductivity is a quantum mechanical phenomenon where certain materials can conduct electric current with zero resistance. Discovered in 1911, this property remained a laboratory curiosity for decades because it only occurred at temperatures chillingly close to absolute zero (-273°C), requiring expensive liquid helium cooling 1 .
The game changed in 1986 with the discovery of high-temperature superconductivity in a ceramic copper-oxide material. "High-temperature" is relative here—these materials operate below -196°C, but that's warm enough to use inexpensive liquid nitrogen as a coolant instead of helium 1 . This breakthrough earned Georg Bednorz and K. Alex Müller the Nobel Prize and launched a global race to find materials that superconduct at ever-higher temperatures.
Most high-temperature superconductors belong to a class of materials called cuprates (copper oxides), many of which have a specific crystal structure known as a perovskite 1 7 . Named after the mineral calcium titanium oxide, perovskite structures have a distinctive arrangement of atoms that creates an ideal environment for the complex electron interactions necessary for high-temperature superconductivity.
What makes perovskites so special? Their crystal architecture serves as a quantum mechanical playground where electrons can interact in unusual ways. In conventional superconductors, atomic vibrations glue electron pairs together. In perovskite cuprates, more exotic mechanisms involving magnetic interactions are at work, though the exact recipe remains one of physics' greatest mysteries 1 5 .
Researchers have identified that the "gene" for high-temperature superconductivity often involves quasi-two-dimensional electronic structures where specific atomic orbitals interact in just the right way within the perovskite framework 5 .
Perovskites have a distinctive ABX₃ crystal structure that creates ideal conditions for electron interactions necessary for high-temperature superconductivity.
Unlike conventional superconductors, perovskites rely on exotic magnetic mechanisms for electron pairing, though the exact process remains mysterious.
While perovskites dominated high-temperature superconductor research for decades, an unexpected newcomer has stolen the spotlight: graphene. When multiple layers of this single-atom-thick carbon material are stacked and twisted at specific "magic angles," they begin to behave in extraordinary ways 1 .
In a groundbreaking October 2025 study published in Nature Physics, a team led by Mitali Banerjee at EPFL revealed a phenomenon called double-dome superconductivity in magic-angle twisted trilayer graphene (MATTG) 1 . This discovery is providing crucial insights that might finally help us understand high-temperature superconductivity.
So how did researchers capture this quantum behavior? The experimental design was as elegant as it was precise:
Scientists created devices by carefully stacking three layers of graphene, with the middle layer twisted at approximately 1.55 degrees relative to the outer layers. This specific "magic angle" creates a unique electronic environment where electrons interact unusually strongly 1 .
The entire graphene stack was sandwiched between thin layers of hexagonal boron nitride, an excellent insulator that protects the delicate quantum states from external interference 1 .
Electrodes and gates were added to allow researchers to precisely control two key parameters: the electron density (how many electrons are in the material) and an electric "displacement field" 1 .
The devices were cooled to temperatures near absolute zero (100 millikelvin), where researchers measured how the electrical resistance changed while varying the electron density, magnetic fields, and applied current 1 .
| Material/Tool | Function in Research |
|---|---|
| Twisted Trilayer Graphene | Platform for creating and tuning exotic quantum states |
| Hexagonal Boron Nitride | Insulating layers that protect delicate quantum effects |
| Electric Displacement Field | Fine-tunes how electrons move and interact in the material |
| Liquid Helium/Nitrogen | Cools experiments to temperatures where superconductivity occurs |
As researchers tuned the electron density in twisted trilayer graphene, they expected to see a single region of superconductivity. Instead, they found two distinct superconducting "domes" separated by a region where superconductivity disappeared 1 .
Even more remarkably, they discovered they could control this double-dome pattern using nothing more than an electric field 1 . This level of precise tuning is incredibly difficult to achieve in perovskite superconductors.
| Feature | First Dome | Second Dome |
|---|---|---|
| Transition to Superconductivity | Sharper, more sudden | Gradual, slower |
| Memory Effect | Present: material responded differently to increasing vs decreasing current | Absent |
| Electron Pairing Mechanism | Possibly different from the second dome | Possibly different from the first dome |
The discovery of two distinct domes suggests that different types of electron pairing might be at work in the same material 1 . Understanding why and how this happens could finally reveal the secret mechanisms behind unconventional superconductivity—knowledge that might allow us to design room-temperature superconductors intentionally rather than discovering them by accident.
The search for new superconductors has traditionally been slow and laborious, relying on trial-and-error and researcher intuition. Today, artificial intelligence is dramatically accelerating this process.
Researchers are now using two-step machine learning approaches that first screen potential chemical compositions for stability, then predict their superconducting properties 3 . This method recently identified six new ferroelectric perovskites out of ten candidates synthesized—an impressive success rate for materials discovery 3 .
Similarly, scientists have developed workflows that combine BCS theory-inspired screening with deep learning models to predict superconducting properties faster than traditional computations 7 . These AI tools can analyze thousands of potential materials in the time it would take humans to examine a handful.
AI systems aggregate known superconductor data and material properties from research databases.
Machine learning algorithms identify subtle correlations between material structures and superconducting properties.
AI suggests promising new material combinations for laboratory testing, dramatically accelerating discovery.
The implications of room-temperature superconductors are staggering. They could enable:
Electricity transmission with zero resistance would dramatically reduce global energy consumption and costs.
MRI machines that don't require expensive cooling systems would make medical imaging more accessible.
Superconducting magnets could efficiently contain and control superheated plasma in fusion reactors.
More stable and scalable qubits would accelerate the development of practical quantum computing.
Maglev trains could become more efficient and widespread with high-temperature superconductors.
Superconducting magnetic energy storage systems could provide grid-scale energy storage solutions.
While the journey continues, the recent breakthroughs in twisted graphene research provide something the field has desperately needed: a tunable platform where scientists can systematically explore the conditions that give rise to high-temperature superconductivity 1 .
As we stand on the brink of a quantum revolution, each discovery—from the first perovskite superconductors to the latest twisted graphene structures—brings us closer to a world where perfect conductivity transforms technology as we know it. The path was paved with perovskites, but it may be graphene that lights the way forward.
The quest continues, now brighter than ever.