New phase of quantum matter discovered that could lead to huge tech leaps

The familiar catalog of matter – solid, liquid, gas, plasma, BEC – just gained a new entry thanks to a custom crystal grown in the laboratory. This new quantum matter phase occurs when electrons and the positive “holes” they leave behind lock into pairs that swirl together in the same spin direction, creating a fluid of light-emitting quasiparticles.

“It’s a new phase of matter, similar to how water can exist as liquid, ice or vapor,” said Luis A. Jauregui, professor of physics and astronomy at UC Irvine.

His team outlines the evidence in a recently published study, staking a claim that moves a half-century-old theory from speculation to the lab bench.

New phase from electron-hole pairs

Researchers first proposed the excitonic insulator in 1965, arguing that a strong enough pull between electrons and holes would cause them to bind and open an energy gap that halts ordinary conduction.

The twist in the Irvine work is that the pairs align their spins rather than cancel them, forming a spin triplet condensate hinted at only in thought experiments until now.

Fresh reviews note that solid evidence for any excitonic insulator has remained elusive because most candidate materials freeze or destabilize before the necessary correlations emerge.

By coaxing a narrowly gapped crystal into the “ultra-quantum limit,” the new experiment clears that hurdle and offers a platform stable at a few kelvin, a temperature range reachable with common cryostats.

The resulting liquid is not a superconductor, yet its charge-neutral pairs can flow without the scattering that heats conventional circuits.

That distinction excites engineers who hunt for ways to move data with spin or valley degrees of freedom rather than raw charge.

Hafnium pentatelluride breaks the rules

The team built their sample from Hafnium pentatelluride, a layered topological material previously known for anomalous thermoelectric behavior.

Strong spin-orbit coupling in the telluride lattice narrows the band gap to fractions of an electron volt, making it fertile ground for electron-hole attraction.

Postdoctoral researcher Jinyu Liu cut the crystal into Hall-bar devices and added gold contacts thinner than a human hair.

The delicate patterning, carried out in Irvine’s cleanroom, preserved the material’s pristine layers while allowing two-terminal transport tests under extreme magnetic fields.

“If we could hold it in our hands, it would glow a bright, high-frequency light,” remarked Jauregui, hinting at the virtual photons tied to each bound pair. The comment highlights how the phase mixes electronic and optical properties in ways still being mapped.

Phase change confirmed in lab

With help from the Los Alamos National Laboratory (LANL), the group exposed the devices to a 70-tesla pulse, roughly 700,000 times stronger than Earth’s field.

Resistance along the current path jumped by orders of magnitude, while the Hall signal collapsed toward zero, classic fingerprints of an insulating state.

Landau quantization simplifies the spectrum in such fields, forcing carriers into discrete Landau levels. Past a critical field, the two lowest levels, one for spin-up electrons, one for spin-down holes, cross and hybridize.

Modeling by theorist Shi-Zeng Lin shows that the crossing seeds the spin-triplet gap measured at about 250 micro-electron-volts.

Because the gap is tied to spin alignment, it survives minor disorder that would kill a conventional charge gap. That resilience hints at practical robustness missing from many fragile quantum phases.

Why does any of this matter?

Using spins instead of electric charges to carry information could cut down on heat in computer chips, which is a major goal for researchers in spintronics.

These special spin-aligned pairs don’t carry any net charge, so they aren’t disrupted by stray electric fields that often cause problems in tiny circuits.

Some scientists think these pairs could even allow spin to flow smoothly without resistance, like how liquid helium flows without friction.

If that’s true, it could lead to strange and useful effects that have only been seen in a few advanced systems, opening the door to new types of tech.

Power without plugs

Exciton liquids naturally couple to light. In Hafnium pentatelluride, recombination is expected to emit photons in the ultraviolet range that can be harvested by integrated diodes.

A chip that recycles this light back into electrical work would, in principle, top itself up while idling, a vision sometimes called a “self-charging computer.”

This idea fits well with brain-inspired computer designs that use low-power memory components instead of energy-hungry traditional circuits.

Recent tests show that spin-based parts can switch using extremely small amounts of energy, much less than what today’s standard chips need.

Electron-hole pairs and space tech

Deep space is awash in protons and heavy ions that flip bits and pummel silicon. Radiation-tolerant design often adds shielding, redundant logic, and hardened gates, all at weight and cost penalties.

A condensate made of neutral pairs sidesteps many single-event upsets because incoming particles interact mainly through charge.

Topological protections further suppress backscattering, according to modeling of magnetic 2D heterostructures that remain stable after megarad doses.

Shieldless computers would lighten probes to Mars and beyond, and their longer lifetimes would shrink the spare-parts budgets of satellite constellations.

Industry already hunts for components that tolerate 1.5 billion-rad totals, a bar this phase could help clear.

Where the science heads next

Jauregui’s group plans to grow wider samples to check whether the phase supports edge currents that could be braided for fault-tolerant qubits.

They also aim to tweak the telluride stoichiometry, nudging the band overlap so the triplet forms at lower fields reachable with tabletop magnets.

Devices that layer hafnium pentatelluride between magnetic or superconducting materials might reveal new ways electron-hole pairs and other particles interact inside the material.

These setups could give engineers new tools for building tiny switches that use just a small amount of spin energy to turn on and off.

Finally, collaborators at the National High Magnetic Field Laboratory are designing long-pulse coils to probe the condensate’s lifetime. If the phase lingers after the field ramps down, chips could run in everyday labs instead of billion-dollar magnets.

The study is published in Physical Review Letters.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–