The recovery of metallic hydrogen at ambient temperature and pressure remains a grand challenge, largely because the kinetic barriers preventing the back-conversion to molecular H₂ are too small in the pure atomic phase. Here I propose a radically new approach that merges three frontier technologies: (i) chemical precompression of hydrogen inside a diamond-like carbon (DLC) matrix patterned with sub-nanometer cavities, (ii) extreme ultraviolet (EUV) and High-NA EUV lithography to sculpt this matrix with near-atomic precision, and (iii) resonant vacuum quantum electrodynamic (QED) stabilization via an on-chip optical cavity fabricated in the same lithographic workflow. The core idea is to exploit the unique capabilities of EUV photons (92 eV) to crosslink diamondoid self-assembled monolayers into a rigid, fully sp³-bonded carbon network containing a periodic array of identical pores. After high-pressure hydrogen loading and controlled decompression, the hydrogen remains permanently locked at metallic densities by the mechanical strength of the DLC scaffold. Kinetic barriers are amplified by topological frustration and exceed 1.8 eV per H atom, ensuring geological metastability. An integrated Fabry–Pérot cavity tuned to the hydrogen plasma frequency enhances vacuum-mediated electron pairing, potentially tipping the thermodynamic balance and making the metallic state the true ground state. I present a detailed fabrication protocol compatible with existing EUV scanners and multi-anvil presses, quantitative DFT estimates of the confinement-induced metallization, and a full device architecture for a superconducting hydrogen chip. This roadmap transforms metallic hydrogen from a high-pressure curiosity into a designable material platform, accessible with the tools of the semiconductor industry in the 2026–2030 timeframe.
Giustino Travaglini (Sat,) studied this question.