Towards a New Quantum Frontier in High Energy Density Science
Lead Research Organisation:
UNIVERSITY OF OXFORD
Department Name: Oxford Physics (Keble Road)
Abstract
Novel facility developments over the next few years are set to transform our ability to explore matter in extreme conditions of temperature, density and pressure. Advances in high-energy lasers, and their co-location at large-scale free-electron laser facilities, such as the European XFEL in Hamburg, will soon allow us routinely to drive matter to pressures exceeding 10 Mbar, and probe it with the brightest x-ray source on the planet. In the US, the construction of the LCLS- II facility will enable independent x-ray-pump, x-ray-probe experiments to take place for the very first time. These capabilities will support novel laboratory-based studies of matter in stellar interior and exoplanetary core conditions, at the nanoscopic scale, and on ultrashort timescales. Most intriguingly, these advances promise to provide access to exotic plasma regimes where quantum behaviour is transferred to the macroscale, constituting a new quantum frontier in high-energy- density science. Here we propose to develop an experimental program to investigate this frontier. By using time-resolved, resonant inelastic x-ray scattering, we will firstly develop efficient approaches to measuring temperatures and valence electronic structure in laboratory-based planetary astrophysics experiments. We then aim to time-resolve electron localization dynamics in systems at increasingly high densities, where core-electron interactions become important. In this context we will study how such electron interactions help mitigate or inhibit phase transitions, metallic ordering, and support mechanisms driving the creation of complex structures such as electrides at high compression. Finally, we aim to explore whether high-energy-density quantum plasmas are able to support core-chemistry, i.e., hybridization and bonding of inner-electrons, by searching for the presence of transient interatomic bonds in proto-molecular systems, and probing their nuclear dynamics on ultrafast time scales.
Organisations
People |
ORCID iD |
| Sam Vinko (Principal Investigator) | |
| Justin Wark (Co-Investigator) |
Publications
Alaa El-Din KK
(2024)
STEP: extraction of underlying physics with robust machine learning.
in Royal Society open science
Amouretti A
(2025)
Isostructural Phase Transition of Fe_{2}O_{3} under Laser Shock Compression.
in Physical review letters
Azadi S
(2023)
Correlation energy of the spin-polarized electron liquid studied using quantum Monte Carlo simulations
in Physical Review B
Azadi S
(2024)
Quantum Monte Carlo study of the phase diagram of the two-dimensional uniform electron liquid
in Physical Review B
Azadi S
(2025)
Electronic temperature driven phase stability and structural evolution of iron at high pressure
in Physical Review B
Azadi S
(2024)
Nonthermal solid-solid phase transition in ferromagnetic iron
in Physical Review B
Azadi S
(2026)
Electronic-entropy-driven solid-solid phase transitions in elemental metals
in Physical Review Materials
Azadi S
(2025)
Lattice stability of ultrafast-heated gold
in Scientific Reports
Azadi S
(2023)
Correlation energy of the paramagnetic electron gas at the thermodynamic limit
in Physical Review B
Campbell T
(2025)
Molecular dynamics framework coupled with smoothed particle hydrodynamics for quantum plasma simulations
in Physical Review Research
Crépisson C
(2025)
Shock-driven amorphization and melting in Fe 2 O 3
in Physical Review B
Forte A
(2025)
Methods for energy dispersive x-ray spectroscopy with photon-counting and deconvolution techniques
in Journal of Applied Physics
Forte A
(2024)
Resonant inelastic x-ray scattering in warm-dense Fe compounds beyond the SASE FEL resolution limit
in Communications Physics
Gawne T
(2024)
Quantifying ionization in hot dense plasmas.
in Physical review. E
Gawne T
(2023)
Quantifying ionization in hot dense plasmas
Gawne T
(2023)
Investigating mechanisms of state localization in highly ionized dense plasmas.
in Physical review. E
Heaton C
(2025)
Measurement of turbulent velocity and bounds for thermal diffusivity in laser shock compressed foams by x-ray photon correlation spectroscopy
in Physical Review E
Kang G
(2025)
Nonequilibrium electron-phonon and electron-ion couplings in warm dense copper
in Applied Surface Science
Krása J
(2024)
Ion emission from warm dense matter produced by irradiation with a soft x-ray free-electron laser
in Matter and Radiation at Extremes
Plummer D
(2026)
Modeling partially ionized dense plasma using wavepacket molecular dynamics
in Physical Review E
Plummer D
(2025)
Ionization calculations using classical molecular dynamics.
in Physical review. E
Pérez-Callejo G
(2024)
Dielectronic satellite emission from a solid-density Mg plasma: Relationship to models of ionization potential depression.
in Physical review. E
Ren S
(2023)
Simulations of collisional effects in an inner-shell solid-density Mg X-ray laser.
in Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
Ren S
(2023)
Non-thermal evolution of dense plasmas driven by intense x-ray fields
in Communications Physics
Shi Y
(2024)
Exploring relaxation dynamics in warm dense plasmas by tailoring non-thermal electron distributions with a free electron laser
in Physics of Plasmas
Strachwitz A
(2026)
Data-efficient learning of exchange-correlation functionals with differentiable DFT
in Machine Learning: Science and Technology
Svensson P
(2023)
Development of a new quantum trajectory molecular dynamics framework.
in Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
Svensson P
(2025)
Modeling of warm dense hydrogen via explicit real-time electron dynamics: Electron transport properties
in Physical Review E
Svensson P
(2024)
Modeling of warm dense hydrogen via explicit real-time electron dynamics: Dynamic structure factors.
in Physical review. E
Vinko S
(2024)
The X-ray science frontier is ultra-short and ultra-intense
in Nature Photonics
| Description | We have developed an advanced technique to investigate the electronic structures of iron compounds under extreme conditions. The method depends on fielding resonant inelastic x-ray scattering (RIXS) with a novel approach that correlates the measurements of the self-amplified spontaneous emission (SASE) spectrum of an x-ray free-electron laser (XFEL) with the RIXS signal, using a dynamic kernel deconvolution with a neural surrogate. This method allows for higher-resolution insights into the behavior of materials subjected to high pressures and temperatures, such as those found in planetary interiors. ? As part of this, we have introduced a machine learning framework designed to solve complex inverse problems in physics. By integrating known physical models into the learning process, this approach enhances the accuracy and robustness of predictions, even when data is noisy. The STEP framework was applied to analyze RIXS spectra, demonstrating its capability to extract meaningful physical information from experimental measurements. This research has significantly advanced our understanding of how materials behave under extreme and rapidly changing conditions, such as those produced by intense laser pulses or shock compression. These conditions are relevant to fields ranging from planetary science and fusion energy to advanced manufacturing and materials design. Across a series of studies, the project revealed that solids like iron and gold may undergo unexpected and structural changes driven by ultrafast heating. The rapid excitation of electrons can destabilize crystal structures, triggering new phase transitions, melting, or even amorphization. This indicates that materials may transform through non-thermal pathways, challenging long-standing assumptions about how solids respond to extreme environments. Furthermore, using time-resolved X-ray diffraction we have seen how iron oxides behaves very differently under rapid compression than under slow, static pressure. Instead of forming previously known high-pressure crystal phases, Fe2O3 undergoes a sudden internal transformation in which its structure remains the same but its volume collapses by about 11%, likely caused by a rapid loss of magnetic order. At higher shock pressures, the material loses its crystalline structure altogether, becoming amorphous, and then transitioning into a liquid-like state. These results underscore the need for caution when extrapolating shock-compression data to geophysical and planetary physics. In parallel, the research developed and validated new computational and experimental methods, including improved molecular-dynamics techniques for modeling ionization and advanced approaches for energy-dispersive X-ray spectroscopy. These tools enhance the accuracy of measurements and simulations used by the wider scientific community. |
| Exploitation Route | Our tools are already being used with the wider high energy density physics community to access electronic structure information in matter in extreme conditions. |
| Sectors | Aerospace Defence and Marine Digital/Communication/Information Technologies (including Software) Energy |
| Description | Equation of state and structure of matter at extreme densities |
| Amount | £124,852 (GBP) |
| Funding ID | 40078320 |
| Organisation | Atomic Weapons Establishment |
| Sector | Private |
| Country | United Kingdom |
| Start | 09/2023 |
| End | 03/2027 |
| Description | Inertial Fusion Energy: Optimising High Energy Density Physics in Complex Geometries |
| Amount | £6,141,929 (GBP) |
| Funding ID | EP/X025373/1 |
| Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 06/2023 |
| End | 06/2028 |
| Description | Temperature measurements and plasticity under uniaxial compression |
| Amount | £113,029 (GBP) |
| Funding ID | 40049673 |
| Organisation | Atomic Weapons Establishment |
| Sector | Private |
| Country | United Kingdom |
| Start | 09/2023 |
| End | 09/2027 |
| Description | X-ray spectroscopy in dynamically compressed matter |
| Amount | £67,966 (GBP) |
| Funding ID | XFH-003-VINKO |
| Organisation | Science and Technologies Facilities Council (STFC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 09/2025 |
| End | 09/2029 |
| Title | Supplementary Materials from STEP: Extraction of underlying Physics with robust Machine Learning |
| Description | step_suppl.tex |
| Type Of Material | Database/Collection of data |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| Impact | A novel approach to performing deconvolution on data with poor signal-to-noise, of particular use for examining spectroscopic data in high energy density physics. |
| URL | https://rs.figshare.com/articles/dataset/Supplementary_Materials_from_STEP_Extraction_of_underlying_... |