New quantum states were discovered where two foreign materials met

At the brink of the encounter between two foreign materials, scientists have discovered a completely new state of matter. This strange phase is called “quantum liquid crystal” and does not follow the rules of solids, liquids, gases, and even plasma.

Instead, it acts in its own symmetry logic that can one day help to operate in extreme environments.

Where the quantum world collides

Rutgers-led research published on June 13 Science Advancesexplores what happens when a conductive material called Weyl semi-differentiated contacts a magnetic insulator called spin ice. Each of these materials is exotic. However, when layers are placed in thin sandwiches and placed under a strong magnetic field, the boundary between them reveals unexpected behavior.

“We observe new quantum phases that only emerge when these two materials interact,” said lead author Tsung-Chi Wu, who recently received his PhD in physics from Rutgers. “This creates a new quantum topological state on high magnetic fields that was previously unknown.”

Electronics flow in strange patterns

At the interface between the two materials, the electrons in Weyl Semimetal have different roles based on directions. This directed behavior is called Electron anisotropywhich means that the material has better power in some directions than in others.

In fact, the conductivity drops sharply at six specific angles throughout the 360-degree circle. As the magnetic field increases further, electrons begin to flow in two opposite directions simultaneously – the sudden movement of symmetry marks the emergence of new quantum phases.

This symmetry disruption is a hallmark of quantum liquid crystals and proposes that physics-rich physics can lead to useful applications.

Why this matters

Understanding and controlling the behavior of materials at their interfaces is key to building better quantum devices, especially in areas such as sensing, computing and communication. The Rutgers team believes that the discovery can enable new sensors to detect magnetic fields under extreme conditions, such as in space or in internal high-energy particle accelerators.

“By understanding how electrons move across these special materials, scientists can potentially design the magnetic fields of a new generation of ultra-sensitive quantum sensors that are most effective under extreme conditions,” Wu said.

What are Weil’s Half Method and Spinning Ice?

Weyl Semimetals are materials, and due to the special granular excitation called Weyl Fermions, the electricity flows with little resistance. These fermions mimic relativistic particles without mass, resulting in a unique surface state known as the Fermi arc.

Spin ice, on the other hand, is a magnetic material in which magnetic moments (such as tiny strip magnets inside each atom) are arranged in a frustrating pattern, similar to the location of hydrogen atoms in water ice. This unusual magnetic structure creates phenomena such as emerging magnetic monopoles and complex spin dynamics.

Key Discovery

• When stratified, Weyl Semimetals and Spin ICE form a sharp interface in which the behavior of electrons depends on direction.
• At low temperatures and high magnetic fields, the interface reveals a new quantum liquid crystal phase with rotational symmetry fracture.
• The electrons suddenly flow in two opposite directions, marking the dramatic phase shift of 9 Tesla and above.
• The angular magnetic magnification shows six times symmetry at the low field, transitioning to double symmetry at the high field.
• These effects are driven by interface coupling between mobile electrons and spin excitation in spin ice.

Challenges of building interfaces

Building such a complex material stack is not easy. Researchers have spent years developing a method to grow sharp layers on EU atoms₂ir₂o₇ (Weyl Semimetal) and Dy₂ti₂o₇ (Spin Ice) Use pulsed laser deposition and in-situ epitaxial.

The interface requires almost perfect observation of the effect. “Ultra-low temperatures and high magnetic fields are crucial to observing these new phenomena,” Wu said. The measurement was conducted at the National High Magnetic Field Laboratory in Tallahassee, Florida.

Teamwork, deep modeling

This study is the result of a close collaboration between experiments and theory. Wu believes theoretical physicist Jedediah Pixley and postdoctoral researcher Yueqing Chang help explain complex data. “It took us more than two years to understand the experimental results,” Wu said.

He added: “The collaboration of experimental theory really makes work possible.”

What’s next?

By adjusting the material or replacing spin ice with a quantum version, researchers hope to discover the stranger state of matter. Their work opens the door to exploring heterogeneous structures made of other closely related materials, which could lead to devices that compute, calculate or store information in entirely new ways.

“This is just the beginning,” Wu said. “When new quantum materials and their interactions are combined into heterostructures, there are multiple possibilities.”

For now, one thing is certain: something strange and wonderful happens when the quantum world of magnetism and topology collides.

Magazine: Science Advances

doi: 10.1126/sciadv.adr6202

Article title: Electron anisotropy and rotational symmetry break at Weyl/Spin ICE interface

Publication date: June 13, 2025

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