Title: Origin of Transitions between Metallic and Insulating States in Simple Metals

Abstract

Unifying principles that underlie recently discovered transitions between metallic and insulating states in elemental solids under pressure are developed. Using group theory arguments and first principles calculations, we show that the electronic properties of the phases involved in these transitions are controlled by symmetry principles not previously recognized. The valence bands in these systems are described by simple and composite band representations constructed from localized Wannier functions centered on points unoccupied by atoms, and which are not necessarily all symmetrical. The character of the Wannier functions is closely related to the degree of s-p(-d) hybridization and reflects multi-center chemical bonding in these insulating states. The conditions under which an insulating state is allowed for structures having an integer number of atoms per primitive unit cell as well as re-entrant (i.e., metal-insulator-metal) transition sequences are detailed, resulting in predictions of novel behavior such as phases having three-dimensional Dirac-like points. The general principles developed are tested and applied to the alkali and alkaline earth metals, including elements where high-pressure insulating phases have been identified or reported (e.g., Li, Na, and Ca).

Authors:

Naumov, Ivan I. ^[1]; Hemley, Russell J. ^[1]

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+ Show Author Affiliations

1. Carnegie Inst. of Washington, Argonne, IL (United States). Geophysical Lab.

Publication Date:

Fri Apr 17 00:00:00 EDT 2015

Research Org.:

Carnegie Inst. of Science, Argonne, IL (United States); Energy Frontier Research Centers (EFRC) (United States). Energy Frontier Research in Extreme Environments (EFree)

Sponsoring Org.:

USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1338329

Alternate Identifier(s):

OSTI ID: 1180188

Grant/Contract Number:  

NA0002006; SC0001057; SC-0001057

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review Letters

Additional Journal Information:

Journal Volume: 114; Journal Issue: 15; Journal ID: ISSN 0031-9007

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY