| Feb 04, 2026 |
Scientists have developed an innovative microscope that uses the ultimate sensor – a single atom – to reveal the invisible energy terrain that guides electrons inside quantum materials.
(Nanowerk News) Imagine trying to read Braille while wearing thick winter gloves; you might feel the general shape of the book, but the story remains a mystery. For decades, this has been the reality for physicists trying to “feel” the invisible energy landscapes that govern how electrons move in quantum materials. Now, researchers at the Weizmann Institute of Science have taken the gloves off.
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In a new study published in Nature (Unknown journal, “Imaging the sub-moiré potential using an atomic single electron transistor”), a team led by Prof. Shahal Ilani unveils the Atomic Single Electron Transistor (Atomic SET), a scanning microscope that uses a single atom as an ultra-sensitive quantum sensor. By scanning this atomic probe across a material, the researchers achieved images with 100 times better resolution than existing state-of-the-art techniques, revealing an unexpectedly intense energy landscape that defies theoretical predictions.
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The Atomic SET opens a new frontier of quantum discovery, promising to reveal the secrets of exotic states of matter that could power the technologies of tomorrow.
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| A single atomic defect acts as a new type of microscope to reveal the electrostatic potential landscape steering the behavior of electrons in quantum materials. (Image: Weizmann Institute of Science)
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From invisible forces to visible maps
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Inside every solid material, electrons move through an invisible energy landscape shaped by the material’s atoms. This landscape determines whether a material conducts electricity, becomes superconducting or hosts entirely new quantum states. Until now, this energy profile was inaccessible to direct imaging because it exists at length scales that are extremely difficult to probe.
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The Atomic SET overcomes this limitation by enabling direct, high-resolution measurements of the electrostatic potential inside quantum materials. The technique is implemented using the group’s recently developed Quantum Twisting Microscope (QTM) platform, which brings a van der Waals material mounted on a scanning tip into contact with a second van der Waals material on a flat substrate, allowing one to be scanned laterally with respect to the other.
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To their surprise, the researchers discovered that when one of the layers contains an atomic defect, such as a missing or substituted atom in the crystal lattice, it forms a highly localized channel for the flow of current between the two layers. Because this atomic defect hosts sharply defined energy levels, current can flow only when these levels are precisely aligned with those of the adjacent van der Waals materials.
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Remarkably, an infinitesimal change in electrostatic potential, on the order of one part per million of the potential produced by a single electron, is sufficient to shift these energy levels and produce a measurable change in current. This makes the Atomic SET the most sensitive detector of electrical potential ever realized at such small length scales.
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By sliding the tip while maintaining contact with the sample, the sensing atom hovers less than a nanometer above the material, scanning its local potential and constructing a real-space map of the energy landscape. The atomic size of the sensor, combined with its extremely close proximity to the sample, yields an unprecedented spatial resolution of about one nanometer – roughly 100 times better than that of existing techniques.
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“For the first time, we can directly see the potential that electrons experience inside a solid,” says lead author Dr. Dahlia Klein. “It’s remarkable that a single atom can be sensitive enough to reveal structures that were previously completely hidden.”
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Peering inside moiré superlattices
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The team demonstrated the power of the Atomic SET on a canonical quantum system: graphene aligned to hexagonal boron nitride. Because these two atomically thin layers have slightly different lattice constants, stacking them together produces a moiré superlattice, an artificial crystal with a long-wavelength repeating pattern. Such superlattices can dramatically reshape electronic behavior and have become central to many of the most important recent discoveries in quantum materials.
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Until now, the energy landscape of this moiré lattice could not be imaged directly. When the researchers applied the Atomic SET to this system, they uncovered a surprising result: The measured potential exhibited an unexpected symmetry and was nearly twice as strong as predicted by existing theoretical models.
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“The fact that such a well-studied system still holds surprises tells us that something fundamental is missing from our current understanding,” says Klein. “And that matters, because this interface is a building block for many of today’s most exciting quantum material platforms.”
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A new tool for quantum discovery
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Beyond this specific system, the Atomic SET represents a powerful new way to explore quantum matter. As the smallest detector of electrical potential, it opens the door to directly visualizing how charge itself organizes, how symmetries break and how exotic quantum phenomena – such as fractional charges and vortex states – emerge inside materials.
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“This isn’t just a better microscope,” says Ilani. “It’s a new way of asking questions about quantum matter – questions that were simply inaccessible before.”
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