Physicists Quantify the Kondo Effect From First Principles for the First Time

Caltech and Yale researchers say computation can now predict the behavior of complicated quantum materials without lab experiments

By LineZotpaper

Published23 October 2026

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Researchers from the California Institute of Technology and Yale University have for the first time precisely quantified the Kondo effect, a longstanding puzzle in quantum physics, using fundamental physics calculations alone. The work, published in Science, is described as a significant step toward predicting the properties of complex materials purely through computation.

The Kondo effect, known since the 1930s, describes how magnetic impurities in metals can cause electrical resistance to rise again below a certain temperature, known as the Kondo temperature, even though metals normally conduct electricity better as they cool. Electrons swarm around the magnetic impurities, canceling out their magnetism and impeding electrical flow.

While scientists understood the cause, precisely predicting when the resistance flip occurs for different combinations of metals and magnetic impurities proved extremely difficult. The electron interactions form a "many-body problem" in which temperature, electron spins and magnetism interact at incredibly small scales, a challenge beyond the reach of even the most powerful supercomputers.

The researchers adopted an ab initio, or "from first principles," approach, borrowing techniques from chemistry to model a single magnetic atom without simplification, as if it were a larger molecule. Using mathematical shortcuts and extensive computing time, they applied basic quantum physics to the modeled atom, repeating calculations to narrow down predictions.

Comparing the modeling to lab measurements, the researchers demonstrated high accuracy. In some cases the new approach was 100 times more accurate than current simplified modeling.

"It is now possible to predict the properties of some complicated materials purely through computation without referring to experiments," says physicist Garnet Chan from Caltech.

The team studied the most basic examples of metals and magnetic atom combinations, describing the work as "a baby step, or a prototype problem" toward more complex phenomena such as high-temperature superconductors and quantum magnets, says Chan. Better prediction methods could allow scientists to develop materials such as superconductors that could transform power grids and large-scale computing, where the most promising materials also have the most complex electron behaviors.

"We are in an exciting era in which faithful predictive quantum descriptions of the full chemical complexity of real materials are coming within reach," says chemist Linqing Peng from Caltech.

Analysis

Why This Matters

The Kondo effect has puzzled physicists for decades because its electron interactions resist precise calculation. Being able to quantify it from first principles removes a major barrier in condensed matter physics.
If the method scales, scientists could screen and design materials for applications such as superconductors, quantum magnets and future computing systems without needing physical samples first.
The result demonstrates that computation can, in some cases, replace experiments as a source of precise predictions about real materials.

Background

The Kondo effect is a cornerstone of quantum physics, first identified in the 1930s. It explains why magnetic impurities in a metal can make electrical resistance climb again at low temperatures, a counterintuitive reversal of normal metallic behavior. The effect emerges from electrons interacting with magnetic atoms on quantum scales, forming what physicists call a many-body problem. For decades, researchers had to rely on real-world experiments and simplified models to pin down its behavior, because full calculations were computationally intractable. This study is the first to combine chemistry-inspired modeling techniques with repeated quantum calculations to capture the effect precisely without experimental input.

Key Perspectives

Caltech and Yale researchers: They see the work as proof that first-principles computation can now predict material-specific behavior of correlated electrons, calling it an exciting era for faithful predictive quantum descriptions and a stepping stone toward studying more complex materials like high-temperature superconductors.

Physicists studying correlated electron systems: The findings offer a new tool for the field, one that could let researchers explore complex quantum materials in silico before investing in laboratory work, though the team itself cautions that the studied examples are a prototype problem.

Critics and skeptics: The results currently apply to the most basic combinations of metals and magnetic atoms. Scaling the approach to more complex materials remains a significant challenge, and the researchers acknowledge there is still a lot of progress to be made before the method becomes a general-purpose predictive tool.

What to Watch

Whether the researchers publish applications of the method to more complex materials, such as candidate superconductors or quantum magnets.
Whether other groups can reproduce the first-principles calculations on different material combinations and confirm the accuracy gains.
How much computing time and cost the approach requires as it is scaled up, which will determine how widely it can be used by the broader physics community.

Sources

Scientists Just Cracked a Quantum Mystery That's Puzzled Physicists For Decades · ScienceAlert

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10 claims in this story checked against 1 source: 9 supported.

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SupportedPhysicists quantified the Kondo effect from first principles for the first time.ScienceAlert: “in a physics first, researchers from the California Institute of Technology (Caltech) and Yale University in the US have managed to precisely quantify the effect in a real material via fundamental physics calculations.”
Partly supportedThe researchers quantified the effect using fundamental physics calculations alone.ScienceAlert: “By comparing the modeling quantifications with lab measurements of the Kondo effect, the researchers proved the high level of accuracy of their prediction system.”
SupportedCaltech and Yale researchers say computation can predict properties of some complicated materials without referring to experiments.ScienceAlert: ““It is now possible to predict the properties of some complicated materials purely through computation without referring to experiments,” says physicist Garnet Chan, from Caltech.”
SupportedThe work was published in Science.ScienceAlert: “The research has been published in Science .”
SupportedThe Kondo effect involves electrical resistance rising below the Kondo temperature when magnetic atoms or impurities are present in metals.ScienceAlert: “Add in a magnetic atom or two, though, and below a certain temperature (the Kondo temperature), electrical resistance starts to rise again.”
SupportedElectrons swarm around magnetic impurities, canceling their magnetism and impeding electrical flow.ScienceAlert: “Electrons swarm around the magnetic impurities in the metal, canceling out the magnetism of the atoms and impeding electrical flow at the same time.”
SupportedPredicting when resistance will rise for different metal and magnetic-impurity combinations is difficult because of complex electron interactions.ScienceAlert: “Such are the complexities of the electron interactions in this ‘many-body problem’ that it’s very tricky to predict when the flip in resistance will happen for different combinations of metals and magnetic impurities.”
SupportedIn some cases, the new approach was 100 times more accurate than current simplified modeling.ScienceAlert: “In some cases, the new approach was 100 times more accurate than current, simplified modeling.”
SupportedChan described the work as “a baby step, or a prototype problem” toward more complex phenomena, including high-temperature superconductors and quantum magnets.ScienceAlert: ““These first materials that we have studied are like a baby step, or a prototype problem, along the way to more complex phenomena such as high-temperature superconductors and quantum magnets,” says Chan.”
SupportedPeng said faithful predictive quantum descriptions of real materials’ full chemical complexity are coming within reach.ScienceAlert: ““We are in an exciting era in which faithful predictive quantum descriptions of the full chemical complexity of real materials are coming within reach,” says chemist Linqing Peng, from Caltech.”