Ferromagnetism and orbital order in a topological ferroelectric.

Phys Rev Lett

CNR-IOM, UOS Cagliari, and Department of Physics, University of Cagliari, Cittadella Universitaria, Cagliari, I-09042 Monserrato, Italy.

Published: November 2012

We explore via density functional calculations the magnetic doping of a topological ferroelectric as an unconventional route to multiferroicity. Vanadium doping of the layered perovskite La(2)Ti(2)O(7) largely preserves electric polarization and produces robust ferromagnetic order and, hence, proper multiferroicity. The marked tendency of dopants to cluster into chains results in an insulating character at generic doping. Ferromagnetism stems from the symmetry breaking of the multiorbital V system via an unusual "antiferro"-orbital order, and from the host's low-symmetry layered structure.

Download full-text PDF

Source
http://dx.doi.org/10.1103/PhysRevLett.109.217202DOI Listing

Publication Analysis

Top Keywords

topological ferroelectric
8
ferromagnetism orbital
4
orbital order
4
order topological
4
ferroelectric explore
4
explore density
4
density functional
4
functional calculations
4
calculations magnetic
4
magnetic doping
4

Similar Publications

We report an experimental study on how topological defects induced by cylindrical air inclusions in the ferroelectric nematic liquid crystal RM734 are influenced by ionic doping, including an ionic surfactant and ionic polymer. Our results show that subtle differences in molecular structure can lead to distinct surface alignments and topological defects. The ionic surfactant induces a planar alignment, with two -1/2 line defects adhering to the cylindrical bubble surface.

View Article and Find Full Text PDF

Ferroelectricity with concomitant Coulomb screening in van der Waals heterostructures.

Nat Nanotechnol

January 2025

State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, China.

Interfacial ferroelectricity emerges in non-centrosymmetric heterostructures consisting of non-polar van der Waals (vdW) layers. Ferroelectricity with concomitant Coulomb screening can switch topological currents or superconductivity and simulate synaptic response. So far, it has only been realized in bilayer graphene moiré superlattices, posing stringent requirements to constituent materials and twist angles.

View Article and Find Full Text PDF

Designing Chiral Organometallic Nanosheets with Room-Temperature Multiferroicity and Topological Nodes.

Nano Lett

January 2025

Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei Institutes of Physical Science (HFIPS), Chinese Academy of Sciences, Hefei, Anhui 230031, China.

Two-dimensional (2D) room-temperature chiral multiferroic and magnetic topological materials are essential for constructing functional spintronic devices, yet their number is extremely limited. Here, by using the chiral and polar HPP (HPP = 4-(3-hydroxypyridin-4-yl)pyridin-3-ol) as an organic linker and transition metals (TM = Cr, Mo, W) as nodes, we predict a class of 2D TM(HPP) organometallic nanosheets that incorporate homochirality, room-temperature magnetism, ferroelectricity, and topological nodes. The homochirality is introduced by chiral HPP linkers, and the change in structural chirality induces a topological phase transition of Weyl phonons.

View Article and Find Full Text PDF

Chiral vortices and their phase transition in ferroelectric/dielectric heterostructures have drawn significant attention in the field of condensed matter. However, the dynamical origin of the chiral phase transition from achiral to chiral polar vortices has remained elusive. Here, we develop a phase-field perturbation model and discover the softening of out-of-plane vibration mode of polar vortices in [(PbTiO)/(SrTiO)] superlattices at a critical epitaxial strain or temperature.

View Article and Find Full Text PDF

Hidden domain boundary dynamics toward crystalline perfection.

Proc Natl Acad Sci U S A

January 2025

Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305.

A central paradigm of nonequilibrium physics concerns the dynamics of heterogeneity and disorder, impacting processes ranging from the behavior of glasses to the emergent functionality of active matter. Understanding these complex mesoscopic systems requires probing the microscopic trajectories associated with irreversible processes, the role of fluctuations and entropy growth, and the timescales on which nonequilibrium responses are ultimately maintained. Approaches that illuminate these processes in model systems may enable a more general understanding of other heterogeneous nonequilibrium phenomena, and potentially define ultimate speed and energy cost limits for information processing technologies.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!