Ferroelectricity with Asymmetric Hysteresis in Metallic LiOsO3 Ultrathin Films

Abstract

Bulk LiOsO3 was experimentally identified as a "ferroelectric" metal where polar distortions coexist with metallicity [Shi et al., Nature Materials 12, 1024 (2013)]. It is generally believed that polar displacements in a "ferroelectric" metal cannot be switched by an external electric field. Here, via comprehensive density functional theory calculations, we demonstrate that a two-unit-cell-thick LiOsO3 thin film exhibits a ferroelectric ground state having an out-of-plane electric dipole moment that can be switched by an external electric field. Moreover, its dipole moment-versus-electric-field hysteresis loop is asymmetric because only surface Li ions'displacements are reversed by external electric field whereas the field-induced force on inner Li atoms are nearly fully screened by itinerant electrons. As a relevant by-product of our study, we also extend the concept of "Born effective charge" to finite metallic systems, and show its usefulness to rationalize the observed effects.

13 pages, 4 figures

References in corpus (5)

• Half-Metallic Graphene Nanoribbons
• Ferroelectric Soft Phonons, Charge Density Wave Instability and Strong Electron-Phonon Coupling in BiS2-Layered Superconductors
• Two-Dimensional Hyperferroelectric Metals: a Different Route to Ferromagnetic-Ferroelectric Multiferroics
• Dual nature of the ferroelectric and metallic state in LiOsO${}_3$
• Metallic ferroelectricity induced by anisotropic unscreened coulomb interaction in LiOsO3

Cited by in corpus (15)

• Two-dimensional Topological Ferroelectric Metal with Giant Shift Current
• Ferroelectric metals in 1T/1T'-phase transition metal dichalcogenide MTe2 bilayers (M = Pt, Pd, and Ni)
• Electrical Detection of Ferroelectric-like Metals through Nonlinear Hall Effect
• Polar Metals Taxonomy for Materials Classification and Discovery
• Linear versus nonlinear electro-optic effects in materials
• Comparative ab initio study of the structural, electronic, magnetic, and dynamical properties of LiOsO${}_3$ and NaOsO${}_3$
• Two-dimensional multiferroic metal with voltage-tunable magnetization and metallicity
• Recent Advances in Unconventional Ferroelectrics and Multiferroics
• Ultrahigh energy storage density in epitaxial AlN/ScN superlattices
• Nonlinear phonon Hall effects in ferroelectrics: its existence and non-volatile electrical control
• Non-volatile Electric Control of Magnetic and Topological Properties of MnBi2Te4 Thin Films
• Energy storage in lead-free Ba(Zr, Ti)O${}_3$ relaxor ferroelectrics: Large densities and efficiencies and their origins
• Coupled magnetic and structural phase transitions in the antiferromagnetic polar metal Pb2CoOsO6 under pressure
• Metallic ferroelectric-ferromagnetic multiferroics in strained EuTiO${}_{3-x}$H${}_x$
• Two-dimensional ferroelectric metal for electrocatalysis