New Emergent Quantum States of Matter at High Pressure

Lead Research Organisation: University of Edinburgh
Department Name: Sch of Physics and Astronomy

Abstract

At ambient conditions, the light alkali metals Li, Na and K are nearly free electron (NFE) metals. But rather than becoming MORE free-electron like when compressed, these metals undergo transitions to unusual and complex structural and electronic forms as a result of density-driven changes in the interactions of the ions and electrons. While such behaviour is expected in all high-density matter, the physics is most evident in the alkali metals due to their NFE behaviour at ambient conditions, and their very high compressibilities. They thus offer a unique insight into the behaviour of all other metals at very high densities. We will exploit our team's expertise in experimental high-pressure physics to create solid and fluid alkali metals at unprecedented densities, and then determine their structural behaviour using x-ray diffraction techniques at synchrotrons, x-ray free electron lasers, and high-energy laser facilities. We will then use electronic structure and quantum-molecular-dynamics calculations to understand the physics behind the observed behaviour, and thereby develop new understanding and improved predictive capabilities in the behaviour of matter at ultra-high densities.

Planned Impact

Knowledge Impact: Developing a detailed knowledge of how simple metals and their melts actually behave at very high compression, and then developing the computational tools to model and understand that behaviour, will generate impact both in the immediate scientific areas of condensed matter physics and high energy-density physics, and also in other areas where high-density matter is prevalent, such as planetary science and inertial confinement fusion (ICF). The new knowledge provided by our research will enable the behaviour of high-density matter to be computed more accurately at conditions even more extreme than we plan to attain here. Economic and societal impacts will derive from the knowledge outcomes of the project, and from the computational methods which will be developed and implemented in standard software packages.

By deepening our understanding of the physical properties of matter at high pressure, we will provide standardized computational tools for calculating electronic and structural properties at high pressures. These tools will help other researchers to understand why high-density materials behave as they do, and make it possible to identify materials with specific desirable properties and even to design new materials.

People and Training: The scale of this project provides an excellent opportunity to train the next generation of researchers in a variety of state-of-the-art x-ray and laser experimental techniques, as well as computation and theoretical modelling. This importance of this training aspect has been recognised by our Project Collaborator AWE who have funded two CASE studentships for the project. Each student and postdoc involved in the research will benefit from the diverse range of experimental and computational techniques we will employ, making them highly employable at new facilities such as ESRF-EBS and European-XFEL, and also at government laboratories, including AWE.

Outreach: The project will impact on society through outreach activities aimed at explaining the exciting magnetic and electronic phenomena found in materials which have correlated electrons and dense electrons. Members of the public, high school students and prospective university students will be able to attend our Science Festivals and Open Days or participate in workshops aimed at de-mystifying the fundamental science in the project.

Publications

10 25 50
 
Description Although we are in the first year of the grant, first results at the Petra, ESRF and Diamond synchrotrons have been obtained. One paper is currently under review
Exploitation Route Too early to say
Sectors Aerospace, Defence and Marine

 
Description The initial results of this award have resulted in the award of am AWE-funded CASE top-up to an EPSRC studenstship to start in 2019.
First Year Of Impact 2019
Sector Aerospace, Defence and Marine
Impact Types Cultural

 
Description CASE Award: Dynamic States in Diamond Anvil Cells
Amount £24,541 (GBP)
Organisation Atomic Weapons Establishment 
Sector Private
Country United Kingdom
Start 09/2019 
End 08/2023
 
Description LLNL 
Organisation Lawrence Livermore National Laboratory
Country United States 
Sector Public 
PI Contribution We have collaborated with LLNL on experiments at LCLS and on the JANUS laser. We have submitted successful beamtime applications with them to Omega and NIF
Collaborator Contribution They have helped twith target preparation, hand-on help during experiments, and advise on data analysis and simulations
Impact Successful beam time applications Publications