Electronic Structure of Condensed Matter<\/h2>\n<\/header>\n
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The most familiar phases of condensed matter are solids and liquids. In these phases, the nuclei are often (but not always) considered classical, while the electrons must be treated quantum mechanically.\u00a0In the McMahon Research Group, we model such phases\u00a0starting\u00a0from the fundamental equations of quantum mechanics.\u00a0Systems of recent interest include dense hydrogen<\/strong> and dense water-ice<\/strong>, described further below.<\/p>\n More exotic condensed phases (e.g., quantum fluids and solids) are described here<\/a>.<\/p>\n A discussion of the methods that we use, including method development is described here<\/a>.<\/p>\n<\/p><\/div>\n<\/section>\n <\/p>\n <\/p>\n <\/p>\n <\/p>\n Dense Hydrogen<\/span><\/strong><\/p>\n Hydrogen and helium are the most abundant elements in the Universe (they are the primary components of Jovian planets, for example). In terms of their electronic structure, they are also the most simple. However, in the condensed phase and under extreme conditions, they exhibit remarkable properties. Hydrogen, for example, is predicted to exhibit ordered quantum states, such as possibilities of a low- or zero-temperature quantum liquid and high-temperature superconductivity.<\/p>\n For a full review, see J. M. McMahon et al., Rev. Mod. Phys.<\/em> 84<\/strong>, 1607–1653 (2012)<\/a>. This article was featured on the cover of Reviews of Modern Physics (left).<\/p>\n<\/p><\/div>\n<\/section>\n <\/p>\n Dense Water-ice<\/span><\/strong><\/p>\n Over the past decade, nearly two thousand confirmed exoplanets\u00a0have been discovered, along with five thousand candidate ones.\u00a0Of these, there have been an\u00a0unexpectedly large number that are Neptune-like. The interiors of such planets\u00a0consist largely of solid water (ice) phases. The properties of\u00a0dense water-ice are\u00a0thus key to understanding a major fraction of the planets that exist in our universe.<\/p>\n Under extreme conditions, water-ice exhibits unusual and potentially remarkable properties. As an example, the image to the right shows a\u00a0predicted partially-ionic, atomic ground-state\u00a0of dense water ice (J. M. McMahon, Phys. Rev. B<\/em> 84<\/strong>, 220104(R) (2011)<\/a>). Given the extremely high zero-point energy of the hydrogen nuclei, it is possible that they undergo\u00a0quantum melting. This would mean that the properties of large, Neptune-like planets are influenced largely by quantum mechanics.<\/p>\n<\/p><\/div>\n <\/p>\n <\/p>\n <\/p>\n The most familiar phases of condensed matter are solids and liquids. In these phases, the nuclei are often (but not always) considered classical, while the electrons must be treated quantum mechanically.\u00a0In the McMahon Research Group, we model such phases\u00a0starting\u00a0from the fundamental equations of quantum mechanics.\u00a0Systems of recent interest include dense hydrogen<\/strong> and dense water-ice<\/strong>, described further below.<\/p>\n More exotic condensed phases (e.g., quantum fluids and solids) are described here<\/a>.<\/p>\n A discussion of the methods that we use, including method development is described here<\/a>.<\/p>\n <\/p>\n![\"RMP_cover\"](\"https:\/\/wpcdn.web.wsu.edu\/wp-labs\/uploads\/sites\/946\/2016\/05\/RMP_cover-396x524.jpg\")
<\/a><\/p>\n<\/p><\/div>\n![\"P21_1p4TPa_top-down\"](\"https:\/\/wpcdn.web.wsu.edu\/wp-labs\/uploads\/sites\/946\/2016\/05\/P21_1p4TPa_top-down-396x402.png\")
<\/a><\/p>\n<\/p><\/div>\n<\/section>\n","protected":false},"excerpt":{"rendered":"Electronic Structure of Condensed Matter<\/h2>\n