For decades, scientists believed that superconductivity—the ability of certain materials to conduct electricity with zero resistance—was fundamentally incompatible with magnetic fields.
Magnetic fields were thought to disrupt the delicate electron pairings that make superconductivity possible.
But now, in a breakthrough that has taken 50 years to confirm, researchers from Brown University have proved that superconductivity can exist inside a magnetic field.
This discovery isn’t just a niche physics problem—it has profound implications for everything from ultra-fast maglev trains to next-generation imaging technology and even our understanding of the fundamental forces of the universe.
So how did scientists finally break a half-century-old assumption? And what does this mean for the future of technology?
Superconductors vs. Magnetic Fields: A Long-Standing Rivalry
Superconductors are fascinating materials.
When cooled to extremely low temperatures, they lose all electrical resistance, allowing electrons to move freely without energy loss.
This phenomenon enables futuristic technologies, like levitating high-speed trains and powerful MRI machines.
However, superconductivity has a known enemy: magnetic fields. Traditionally, strong magnetic fields were believed to disrupt superconductivity by preventing the formation of Cooper pairs—the fundamental electron pairings that enable resistance-free current flow.
Here’s how it works:
- In a superconductor, electrons pair up into Cooper pairs with opposite “spins.”
- These paired electrons glide through the material without scattering, eliminating resistance.
- A magnetic field disrupts this delicate balance by changing the “spin” states of the electrons, creating an imbalance between spin-up and spin-down electrons.
- Without enough electron pairs, resistance returns, and superconductivity breaks down.
For decades, this incompatibility was considered an unbreakable rule—until now.
Breaking the 50-Year Stalemate: The FFLO Phase Confirmed
Back in 1964, four physicists—Peter Fulde, Richard Ferrell, Anatoly Larkin, and Yuri Ovchinnikov—proposed a radical idea.
They suggested that, under the right conditions, superconductivity could still exist inside a magnetic field.
Their theory, known as the FFLO phase, predicted that unpaired electrons wouldn’t destroy superconductivity completely.
Instead, these unpaired electrons would cluster together in distinct regions, creating alternating bands of superconducting and normal-conducting material.
This would allow electricity to flow without resistance, even in the presence of a magnetic field.
The problem? Nobody had ever observed the FFLO phase in action.
Attempts to detect this exotic superconducting state had repeatedly failed—until a team at Brown University, led by Vesna Mitrovic, finally proved it in 2024.
How Scientists Finally Proved It
To confirm the existence of the FFLO phase, Mitrovic’s team used an organic superconducting material—a layered, ultra-thin structure that provided the perfect conditions for testing superconductivity under a magnetic field.
Unlike previous experiments, which were conducted at ultra-cold temperatures, the researchers increased the temperature slightly and used nuclear magnetic resonance (NMR) to directly observe how electrons behaved under a magnetic field.
What they found was extraordinary.
As the magnetic field increased, unpaired electrons gathered in specific regions of the material, forming “pockets” of normal conductivity within the superconducting structure.
These pockets, known as Andreev bound states, acted like “little particles trapped in a box,” according to Mitrovic.
This behavior perfectly matched the predictions made 50 years ago by Fulde, Ferrell, Larkin, and Ovchinnikov—proving once and for all that the FFLO phase is real.
“This really goes beyond the problem of superconductivity,” Mitrovic explained.
“It has implications for explaining many other things in the universe, such as the behavior of dense quarks, the fundamental particles that make up atomic nuclei.”
Why This Matters: The Future of Superconducting Technology
At first glance, this discovery might seem like a niche physics breakthrough.
But in reality, it could revolutionize multiple fields of technology and even fundamental physics.
1. The Future of Maglev Trains
Magnetic levitation (maglev) trains rely on superconductors to generate powerful magnetic fields that allow trains to hover above the tracks, eliminating friction and enabling speeds over 370 mph (600 km/h).
However, traditional superconductors struggle in strong magnetic fields, limiting the efficiency of maglev technology. With the confirmation of the FFLO phase, scientists may now be able to develop superconductors that can function in much stronger magnetic environments, leading to even faster and more efficient maglev systems.
2. Next-Generation Medical Imaging
MRI machines rely on superconducting magnets to create the detailed images used in medical diagnostics. But stronger magnetic fields would allow for even higher-resolution imaging, leading to earlier disease detection and improved treatment planning.
The problem? Traditional superconductors fail in extreme magnetic conditions. If new materials can maintain superconductivity in powerful magnetic fields, it could revolutionize medical imaging technology.
3. Unlocking the Secrets of the Universe
The implications of this breakthrough extend beyond practical technology—it also challenges our understanding of fundamental physics.
The FFLO phase could help explain the behavior of dense quark matter, the substance found inside neutron stars.
Understanding how superconductivity works in extreme environments could provide new insights into the nature of matter under extreme gravitational and magnetic conditions.
The Next Steps: What’s Next for Superconductivity Research?
While proving the FFLO phase is a huge step forward, scientists now face the challenge of harnessing this knowledge to develop practical applications.
Key areas of future research include:
- Discovering new superconducting materials that can sustain the FFLO phase at higher temperatures, making them viable for real-world applications.
- Developing more efficient superconducting magnets for use in maglev trains, power grids, and quantum computing.
- Exploring the role of superconductivity in astrophysics, particularly in understanding neutron stars and other extreme cosmic environments.
Final Thoughts: A 50-Year Mystery, Finally Solved
It took five decades, but scientists have finally proven that superconductivity can survive inside a magnetic field.
The confirmation of the FFLO phase isn’t just a win for physics—it has real-world applications that could transform transportation, medicine, and our understanding of the universe itself.
As researchers continue to explore the boundaries of superconductivity, one thing is certain: the future of technology just got a whole lot more exciting.
Sources: Brown University, Nature Physics
