2009/08/22 by Gianluca Giovannetti, Sanjeev Kumar, Alessandro Stroppa +2
Chemistry · Engineering · Materials Science · Physics and Astronomy · #Ab initio #Ab initio quantum chemistry methods #Antiferromagnetism #Chemistry #Condensed matter physics #Dielectric #Electronic structure #Ferroelectricity #Ion #Ionic bonding #Materials science #Molecule #Multiferroics #Organic and Molecular Conductors Research #Perovskite Materials and Applications #Physical chemistry #Physics #Polarization (electrochemistry) #Quantum mechanics #Solid-state spectroscopy and crystallography #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevlett.103.266401
published as Phys. Rev. Lett. 103, 266401 (2009) · 4 pages, 4 figures
arxiv created 2009/08/22 · openalex publication_date 2009/12/28 · arxiv updated 2015/05/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We show by means of ab initio calculations that the organic molecular crystal TTF-CA is multiferroic: it has an instability to develop spontaneously both ferroelectric and magnetic ordering. Ferroelectricity is driven by a Peierls transition of the TTF-CA in its ionic state. Subsequent antiferromagnetic ordering strongly enhances the opposing electronic contribution to the polarization. It is so large that it switches the direction of the total ferroelectric moment. Within an extended Hubbard model, we capture the essence of the electronic interactions in TTF-CA, confirm the presence of a multiferroic groundstate, and clarify how this state develops microscopically.