Carnegie Researchers Predict Exotic Superionic Carbon Hydride State Within Extreme Pressure Interiors of Neptune and Uranus

Carnegie researchers identify a new quasi-1D superionic state of carbon hydride in ice giants, potentially explaining unusual planetary magnetic fields.

By: AXL Media

Published: Apr 3, 2026, 11:19 AM EDT

Source: Information for this report was sourced from Carnegie Institution for Science

Probing the Exotic Physics of Ice Giant Interiors

The deep interiors of Uranus and Neptune remain some of the most mysterious environments in our solar system, characterized by extreme temperatures and crushing pressures. Scientists have long theorized that these planets contain intermediate layers of unconventional "hot ices" located beneath their thick hydrogen and helium atmospheres. Recent computational research published in Nature Communications suggests that these regions are home to a quasi one dimensional superionic state of carbon hydride. This finding provides a new framework for understanding the dynamic processes that shape ice giants, offering clues into how heat and matter behave miles beneath the visible cloud tops.

The Mechanics of the Superionic State of Matter

Superionic materials represent a unique middle ground between the solid and liquid phases of matter. In this exotic state, one type of atom remains locked within a rigid crystalline framework while another becomes mobile, flowing through the lattice like a liquid. In the case of carbon hydride deep within planetary cores, the carbon atoms form an ordered hexagonal structure. Meanwhile, the hydrogen atoms become highly mobile, yet their movement is not chaotic. Instead, they follow specific pathways that define the electrical and thermal characteristics of the material under extreme conditions.

Spiral Hydrogen Pathways and One Dimensional Conductivity

The most striking feature of this newly predicted phase is the directional nature of atomic motion. Using high performance computing and machine learning, researchers Cong Liu and Ronald Cohen simulated pressures ranging from 500 to 3,000 gigapascals. They discovered that hydrogen atoms move preferentially along well defined helical or spiral pathways embedded within the carbon framework. This quasi one dimensional behavior is a departure from typical three dimensional diffusion and suggests that the transport of electricity and heat within Neptune and Uranus may be highly specialized, following the orientation of these microscopic spirals.