Graphene Hyperbolic Pseudospheres Demonstrate High Stability under Harsh Conditions and Large Deformations

Graphene, a single-layer sheet of carbon atoms, holds immense promise for future technologies, but creating stable, curved structures from this material remains a significant challenge. Researchers led by T. P. C. Klaver, R. Gabbrielli, and V. Tynianska, with contributions from A. Iorio and D. Legut, now demonstrate a method for producing and rigorously testing the stability of graphene hyperbolic pseudospheres, structures with potential applications in areas mimicking aspects of classical or gravitational physics. The team successfully simulates the creation of these curved surfaces using molecular dynamics, a process that naturally incorporates stabilizing defects within the graphene itself. Crucially, their simulations reveal that these pseudospheres withstand substantial deformation and elevated temperatures without fracturing, representing a major step towards realising functional, curved graphene devices and enabling predictive design before experimental fabrication.

Graphene Pseudospheres Mimic Curved Spacetime

Scientists are creating carbon structures with unique, saddle-like curvature, known as pseudospheres, to explore fundamental physics concepts related to curved spacetime and potentially quantum gravity. This research leverages graphene’s distinctive electronic properties to build a platform for investigating phenomena difficult to observe directly in the universe, such as the Hawking-Unruh effect. The team aims to create robust structures suitable for experimental investigation of these complex theories. The research centers on creating negative curvature, resembling pseudospheres, and utilizes graphene’s inherent properties linked to its Dirac-like behavior and Weyl symmetry, connecting the material’s characteristics to concepts in curved spacetime.

This approach allows researchers to simulate aspects of gravity, offering a novel way to study phenomena in extreme environments. The team employed molecular dynamics simulations to model the creation and behavior of these carbon pseudospheres, utilizing a process of nano-extrusion, stretching and shaping the carbon material, followed by annealing to relieve stress and stabilize the structure. The simulations modeled interactions between carbon atoms using the REBO potential and rigorously tested the structures’ mechanical stability under stress from elongation and shearing, and simulated annealing at high temperatures. The simulations successfully created carbon pseudospheres with negative curvature, demonstrating remarkable stability even under significant stress and high temperatures.

The structures exhibited only a small deviation from ideal curvature, suggesting they are robust enough for experimental creation and use in fundamental physics investigations. Future work will focus on experimentally creating and testing these structures, exploring whether other materials, such as boron nitride, can be formed using the same techniques. A more detailed analysis of the impact of defects on the structures’ properties is also planned. Ultimately, the goal is to use these structures to conduct experiments exploring analogies to curved spacetime and test predictions of quantum gravity. This research represents a significant step towards creating a tangible platform for exploring fundamental physics using materials science and computational modeling.

Stable Hyperbolic Graphene via Molecular Dynamics

Scientists have successfully created stable, curved graphene surfaces resembling hyperbolic pseudospheres using molecular dynamics simulations. The research demonstrates a novel methodology for constructing these structures, beginning with a nano-extrusion process where carbon atoms are forced into a three-dimensional shape. This initial extrusion creates an unstable carbon precursor, which is then transformed into realistic, mechanically stable graphene through high-temperature annealing. Crucially, point defects naturally arise during annealing, stabilizing the graphene in the desired hyperbolic shape without introducing high residual stresses.

The team constructed hyperbolic pseudospheres with specific parameters, scaling the resulting structure to a defined size. Simulations involved embedding these pseudospheres within graphene sheets, utilizing a limited number of atoms per system and requiring significant computational resources. To approximate the complex hyperbolic shape, the researchers merged cone slices, creating a body that guided the carbon atoms during extrusion and annealing. A strong potential temporarily forced atoms onto the mathematical hyperbolic surface. After “soft-annealing” and removal of the potential, the graphene retained a shape closely resembling the initial template, demonstrating remarkable stability even under large mechanical deformation. Tests revealed the pseudospheres remained stable following both shearing and elongation, confirming their feasibility for experimental preparation and testing. This methodology offers a practical route to creating curved graphene surfaces of almost any shape, paving the way for applications in areas such as desalination filters.

Stable Hyperbolic Graphene via Defect Engineering

This research demonstrates a novel methodology for creating and stabilizing curved graphene structures, specifically hyperbolic pseudospheres, through molecular dynamics simulations. The team successfully produced these structures by first extruding carbon atoms into a precursor form, then annealing it at high temperature to form realistic, polycrystalline graphene. Crucially, point defects naturally arise during this process, stabilizing the graphene in the desired hyperbolic shape without introducing high residual stresses. The resulting pseudospheres exhibited remarkable stability under significant deformation and high temperatures, maintaining their form even after shearing or elongation.

The simulations reveal that attaching flat graphene sheets to the edges of the pseudosphere further enhances stability, bringing the carbon atoms remarkably close to the mathematically defined hyperbolic surface. This approach offers a practical means of pre-testing the feasibility of creating complex curved graphene shapes before attempting experimental fabrication. The team acknowledges that the simulations rely on specific interatomic potentials and that the resulting material properties may differ in real-world experiments. Future work will focus on exploring the potential of these structures in applications inspired by classical or gravity, and investigating the impact of different parameters on their stability and mechanical properties.