Unusual Ferroelectricity Induced by the Jahn-Teller Effect: A Case Study on Lacunar Spinel Compounds

Abstract

The Jahn-Teller effect refers to the symmetry-lowering geometrical distortion in a crystal (or non-linear molecule) due to the presence of a degenerate electronic state. Usually, the Jahn-Teller distortion is not polar. Recently, GaV4S8 with the lacunar spinel structure was found to undergoes a Jahn-Teller distortion from cubic to ferroelectric rhombohedral structure at TJT = 38K. In this work, we carry out a general group theory analysis to show how and when the Jahn-Teller effect gives rise to ferroelectricity. On the basis of this theory, we find that the ferroelectric Jahn-Teller distort in GaV4S8 is due to the non-centrosymmetric nature of the parent phase and strong electron-phonon interaction related to two low-energy T2 phonon modes. Interestingly, GaV4S8 is not only ferroelectric, but also ferromagnetic with the magnetic easy axis along the ferroelectric direction. This suggests that GaV4S8 is a multiferroic in which an external electric field may control its magnetization direction. Our study not only explains the Jahn-Teller physics in GaV4S8, but also paves a new way for searching and designing new ferroelectrics and multiferroics.

Phys. Rev. B rapid communication (To be published)

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Cited by in corpus (19)

• Discovery of Intrinsic Ferromagnetic Ferroelectricity in Transition Metal Halides Monolayer
• Characteristics of ferroelectric-ferroelastic domains in N{é}el-type skyrmion host GaV${}_4$S${}_8$
• On the multiferroic skyrmion-host GaV4S8
• Two-dimensional Ferroelectric Ferromagnetic Half Semiconductor in VOF monolayer
• Polar and magnetic order in GaV4Se8
• Possible emergence of a skyrmion phase in ferroelectric GaMo${}_4$S${}_8$
• Cooperative cluster-Jahn-Teller effect as a possible route to antiferroelectricity
• Magnetic avalanche of non-oxide conductive domain walls
• Orbital-Order Driven Ferroelectricity and Dipolar Relaxation Dynamics in Multiferroic GaMo${}_4$S${}_8$
• Lattice dynamics and electronic excitations in a large family of lacunar spinels with a breathing pyrochlore lattice structure
• Optical conductivity in multiferroic GaV${}_4$S${}_8$ and GeV${}_4$S${}_8$: Phonons and electronic transitions
• Relaxation dynamics of modulated magnetic phases in skyrmion host GaV4S8: an ac magnetic susceptibility study
• Excitations and relaxation dynamics in multiferroic GeV4S8 studied by THz and dielectric spectroscopy
• Antipolar transitions in GaNb${}_4$Se${}_8$ and GaTa${}_4$Se${}_8$
• Antiskyrmions and Bloch Skyrmions in Magnetic Dresselhaus Metals
• Bond Ordering and Molecular Spin-Orbital Fluctuations in the Cluster Mott Insulator GaTa${}_4$Se${}_8$
• Spin dynamics in the skyrmion-host lacunar spinel GaV4S8
• Magnetoelectric effect arising from a field-induced pseudo Jahn-Teller distortion in a rare earth magnet
• Optical, dielectric, and magnetoelectric properties of ferroelectric and antiferroelectric lacunar spinels