However, these “conventional” superconductors only operate at extremely cold temperatures. They must be kept in specialized cooling systems to remain in their superconducting state. If materials could superconduct at warmer, more practical temperatures, they could transform modern technology — from creating energy grids that waste no power to enabling more functional quantum computers. To reach that goal, researchers at MIT and other institutions are exploring “unconventional” superconductors, materials that defy the rules of traditional ones and may lead to the next big breakthrough.

MIT’s Magic-Angle Graphene Discovery

In a major step forward, MIT physicists have observed clear evidence of unconventional superconductivity in “magic-angle” twisted tri-layer graphene (MATTG). This unique material is created by stacking three atom-thin sheets of graphene at a very specific angle. That tiny twist dramatically alters the material’s properties, giving rise to strange and promising quantum effects.

While earlier studies hinted that MATTG might host unconventional superconductivity, the new findings, published in Science, offer the most direct confirmation to date.

A New Look at the Superconducting Gap

The MIT team successfully measured MATTG’s superconducting gap, which indicates how strong a material’s superconducting state is at different temperatures. They found that the gap in MATTG looked completely different from what is seen in conventional superconductors. This difference suggests that the way MATTG becomes superconducting relies on a distinct, unconventional mechanism.

“There are many different mechanisms that can lead to superconductivity in materials,” explains co-lead author Shuwen Sun, a graduate student in MIT’s Department of Physics. “The superconducting gap gives us a clue to what kind of mechanism can lead to things like room-temperature superconductors that will eventually benefit human society.”

The team made this discovery with a new experimental system that lets them directly observe how the superconducting gap forms in two-dimensional materials. They plan to use the technique to study MATTG and other 2D materials in more detail, hoping to identify new candidates for advanced technologies.

“Understanding one unconventional superconductor very well may trigger our understanding of the rest,” says Pablo Jarillo-Herrero, the Cecil and Ida Green Professor of Physics at MIT and senior author of the study. “This understanding may guide the design of superconductors that work at room temperature, for example, which is sort of the Holy Grail of the entire field.”

The Origins of Twistronics

Graphene is made of a single layer of carbon atoms arranged in a hexagonal pattern that looks like chicken wire. Scientists can peel off a sheet of graphene from graphite (the same material in pencil lead) to study its properties. In the 2010s, researchers predicted that stacking two layers of graphene at a very precise angle could create new electronic behaviors.

In 2018, Jarillo-Herrero’s group became the first to experimentally produce this so-called “magic-angle” graphene and reveal its extraordinary properties. That work launched a new field of research known as “twistronics,” which studies the surprising effects that emerge when ultra-thin materials are stacked and twisted at exact orientations. Since then, the team and others have explored a variety of graphene structures with multiple layers, revealing further signs of unconventional superconductivity.

How Electrons Cooperate

Superconductivity occurs when electrons form pairs rather than scattering apart as they move through a material. These paired electrons, known as “Cooper pairs,” can travel without resistance, creating a perfect flow of current.

“In conventional superconductors, the electrons in these pairs are very far away from each other, and weakly bound,” says co-lead author Jeong Min Park PhD ’24. “But in magic-angle graphene, we could already see signatures that these pairs are very tightly bound, almost like a molecule. There were hints that there is something very different about this material.”

Probing the Quantum World Through Tunneling

To prove that MATTG truly exhibits unconventional superconductivity, the MIT researchers needed to measure its superconducting gap directly. As Park explains, “When a material becomes superconducting, electrons move together as pairs rather than individually, and there’s an energy ‘gap’ that reflects how they’re bound. The shape and symmetry of that gap tells us the underlying nature of the superconductivity.”

To do this, scientists used a quantum-scale technique known as tunneling spectroscopy. At this level, electrons act both as particles and as waves, which allows them to “tunnel” through barriers that would normally stop them. By studying how easily electrons can tunnel through a material, researchers can learn how strongly they are bound inside it. However, tunneling results alone don’t always prove that a material is superconducting, making direct measurements both crucial and challenging.

A Closer Look at the Superconducting Gap

Park’s team developed a new platform that combines tunneling spectroscopy with electrical transport measurements, which involve tracking how current moves through the material while monitoring its resistance (zero resistance means it’s superconducting).

Using this method on MATTG, the researchers could clearly pinpoint the superconducting tunneling gap — it appeared only when the material reached zero resistance, the defining mark of superconductivity. As they changed the temperature and magnetic field, the gap displayed a sharp V-shaped curve, very different from the smooth, flat pattern typical of conventional superconductors.

This unusual V shape points to a new mechanism behind MATTG’s superconductivity. Although the exact process is still unknown, it’s now clear that this material behaves unlike any conventional superconductor discovered before.

A Different Kind of Electron Pairing

In most superconductors, electrons pair up due to vibrations in the surrounding atomic lattice, which gently push them together. Park believes MATTG operates differently.

“In this magic-angle graphene system, there are theories explaining that the pairing likely arises from strong electronic interactions rather than lattice vibrations,” she says. “That means electrons themselves help each other pair up, forming a superconducting state with special symmetry.”

The Path Ahead: Next-Generation Quantum Materials

The MIT team plans to apply their new experimental setup to study other twisted and layered materials.

“This allows us to both identify and study the underlying electronic structures of superconductivity and other quantum phases as they happen, within the same sample,” Park explains. “This direct view can reveal how electrons pair and compete with other states, paving the way to design and control new superconductors and quantum materials that could one day power more efficient technologies or quantum computers.”

This research received support from the U.S. Army Research Office, the U.S. Air Force Office of Scientific Research, the MIT/MTL Samsung Semiconductor Research Fund, the Sagol WIS-MIT Bridge Program, the National Science Foundation, the Gordon and Betty Moore Foundation, and the Ramon Areces Foundation.

“What you see on these images is not the black hole itself, but rather the hot matter in its immediate vicinity,” explains Prof. Luciano Rezzolla of Goethe University Frankfurt, whose team played a crucial role in the discovery. “As long as the matter is still rotating outside the event horizon — before being inevitably pulled in — it can emit final signals of light that we can, in principle, detect.”

Einstein’s Theory and the Mystery of Black Holes

These striking images reveal what scientists call the “shadow” of a black hole, offering a new way to probe the physics behind these mysterious cosmic giants. For over a century, Einstein’s general theory of relativity has been the foundation of our understanding of space and time. It predicts the existence of black holes and the event horizon, a boundary beyond which nothing — not even light — can escape.

“There are, however, also other, still hypothetical theories that likewise predict the existence of black holes,” Rezzolla notes. “Some of these approaches require the presence of matter with very specific properties or even the violation of the physical laws we currently know.”

Testing Einstein’s Ideas With Black Hole Shadows

In collaboration with colleagues from the Tsung-Dao Lee Institute in Shanghai (China), Rezzolla and his team proposed a new way to test these alternative theories. Their work, published in Nature Astronomy, outlines how future black hole observations could help confirm or challenge Einstein’s model of gravity. Until now, there has not been enough data to verify or reject competing ideas, but that may soon change through detailed analysis of black hole shadow images.

“This requires two things,” Rezzolla explains. “On the one hand, high-resolution shadow images of black holes to determine their radius as accurately as possible, and on the other hand, a theoretical description of how strongly the various approaches deviate from Einstein’s theory of relativity.”

Simulations Reveal How Theories Diverge

To tackle this, the team produced a thorough framework describing how different theoretical types of black holes would vary from Einstein’s predictions and how those differences would appear in images. They used advanced three-dimensional computer simulations to reproduce the motion of matter and magnetic fields in the warped spacetime surrounding black holes. From these simulations, they created synthetic images of the glowing plasma that circles these immense objects.

“The central question was: How significantly do images of black holes differ across various theories?” says lead author Akhil Uniyal of the Tsung-Dao Lee Institute. The researchers identified clear patterns that, with sharper images in the future, could help scientists determine which theory best matches reality. Although today’s EHT resolution cannot yet detect these fine distinctions, improvements in technology will gradually make such comparisons possible. To prepare for this, the physicists developed a universal description of black holes that can encompass many different theoretical frameworks.

Einstein’s Theory Still Holding Strong — for Now

“One of the EHT collaboration’s most important contributions to astrophysics is turning black holes into testable objects,” Rezzolla emphasizes. “Our expectation is that relativity theory will continue to prove itself, just as it has time and again up to now.” So far, the findings remain consistent with Einstein’s theory, although uncertainties in measurement mean that only a few exotic ideas have been ruled out. For example, the black holes in M87 and the Milky Way are almost certainly not “naked singularities” (without an event horizon) or wormholes. Still, Rezzolla notes, “Even the established theory must be continuously tested, especially with extreme objects like black holes.” If Einstein’s model were ever shown to fail, it would mark a revolutionary moment in physics.

A New Era of Cosmic Observation

The EHT provides an unprecedented opportunity for these investigations. By combining data from multiple large radio telescopes across the world, it effectively creates a telescope as large as Earth, capable of capturing fine details around black holes. Plans are already underway to add more observatories to the network and, eventually, to include a radio telescope in space, which would greatly boost its resolution.

Such advancements could make it possible to perform truly definitive tests of competing black hole theories. According to the new study, this would require achieving an angular resolution of less than one millionth of an arcsecond — roughly equivalent to spotting a coin on the surface of the Moon from Earth. While that level of precision is not yet possible, scientists expect it to be within reach in the coming years, potentially unlocking a new chapter in our understanding of gravity and the universe itself.

The research was led by scientists from the Second Institute of Oceanography, Ministry of Natural Resources (SIO-MNR), and the Nanjing Institute of Geography and Limnology (NIGLAS) of the Chinese Academy of Sciences. Their results were published in Science Advances on Nov. 5.

The Ocean’s Role in Earth’s Carbon Balance

The Southern Ocean is a major regulator of the global carbon cycle, absorbing a large share of the carbon released by human activity. Yet despite its importance, it remains the “largest source of uncertainty” in global CO₂ flux calculations.

That uncertainty comes from a lack of winter observations. For months each year, the Southern Ocean lies in complete darkness and is lashed by extreme weather, making direct measurement nearly impossible. During this time, the region becomes an “observational black box.” Traditional satellites, which depend on reflected sunlight (passive sensors) to detect ocean properties, cannot collect data under these conditions, leaving scientists reliant on incomplete or estimated models.

Using Lasers to See in the Dark

To overcome this limitation, the researchers used an advanced approach that combined 14 years of data from a laser-based satellite instrument called LIDAR (on the CALIPSO mission) with machine learning analysis.

LIDAR, unlike passive sensors, sends out its own light signals, working similarly to radar but with lasers instead of radio waves. This technology allowed the team to observe the ocean even during the polar night and create the first continuous, observation-based record of winter CO₂ exchange in the Southern Ocean.

The results revealed that earlier estimates had missed nearly 40% of the Southern Ocean’s wintertime CO₂ output. “Our findings suggest that the Southern Ocean’s role in the global carbon cycle is more complex and dynamic than previously known,” said Prof. Kun Shi of NIGLAS.

Rethinking the Ocean’s Carbon Dynamics

Beyond updating the numbers, the study redefines how scientists understand carbon movement in the Southern Ocean. The team introduced a new “three-loop framework” to explain how CO₂ exchange varies across different regions.

In the Antarctic Loop (south of 60°S), physical factors such as sea ice and salinity are the main drivers of CO₂ exchange. In the Polar Front Loop (45°S-60°S), the interaction between atmospheric CO₂ and biological activity (chlorophyll) becomes more influential. Meanwhile, in the Subpolar Loop (north of 45°S), sea surface temperature plays the dominant role.

Global Climate Implications

Filling this long-standing data gap could lead to more accurate global carbon budgets, which form the foundation of climate projections used by organizations such as the Intergovernmental Panel on Climate Change (IPCC).

This research highlights the power of combining active satellite sensing with machine learning to study the planet’s most remote and dynamic regions, opening new possibilities for understanding the Earth’s climate system year-round.