TY - JOUR
T1 - Evidence for Electronically Driven Ferroelectricity in a Strongly Correlated Dimerized BEDT-TTF Molecular Conductor
AU - Gati, Elena
AU - Fischer, Jonas K.H.
AU - Lunkenheimer, Peter
AU - Zielke, David
AU - Köhler, Sebastian
AU - Kolb, Felizitas
AU - Von Nidda, Hans Albrecht Krug
AU - Winter, Stephen M.
AU - Schubert, Harald
AU - Schlueter, John A.
AU - Jeschke, Harald Olaf
AU - Valentí, Roser
AU - Lang, Michael
N1 - Funding Information:
This work was supported by the Deutsche Forschungsgemeinschaft through the Transregional Collaborative Research Centers TR49 and TRR 80. J. A. S. acknowledges support from the Independent Research and Development program from the NSF while working at the Foundation. We thank Ryui Kaneko for theoretical input, and Mamoun Hemmida, Martin Dressel, and Tomislav Ivek for useful discussions of the magnetic properties.
Publisher Copyright:
© 2018 American Physical Society. American Physical Society.
PY - 2018/6/14
Y1 - 2018/6/14
N2 - By applying measurements of the dielectric constants and relative length changes to the dimerized molecular conductor κ-(BEDT-TTF)2Hg(SCN)2Cl, we provide evidence for order-disorder type electronic ferroelectricity that is driven by the charge order within the (BEDT-TTF)2 dimers and stabilized by a coupling to the anions. According to our density functional theory calculations, this material is characterized by a moderate strength of dimerization. This system thus bridges the gap between strongly dimerized materials, often approximated as dimer-Mott systems at 1/2 filling, and nondimerized or weakly dimerized systems at 1/4 filling, exhibiting a charge order. Our results indicate that intradimer charge degrees of freedom are of particular importance in correlated κ-(BEDT-TTF)2X salts and can create novel states, such as electronically driven multiferroicity or charge-order-induced quasi-one-dimensional spin liquids.
AB - By applying measurements of the dielectric constants and relative length changes to the dimerized molecular conductor κ-(BEDT-TTF)2Hg(SCN)2Cl, we provide evidence for order-disorder type electronic ferroelectricity that is driven by the charge order within the (BEDT-TTF)2 dimers and stabilized by a coupling to the anions. According to our density functional theory calculations, this material is characterized by a moderate strength of dimerization. This system thus bridges the gap between strongly dimerized materials, often approximated as dimer-Mott systems at 1/2 filling, and nondimerized or weakly dimerized systems at 1/4 filling, exhibiting a charge order. Our results indicate that intradimer charge degrees of freedom are of particular importance in correlated κ-(BEDT-TTF)2X salts and can create novel states, such as electronically driven multiferroicity or charge-order-induced quasi-one-dimensional spin liquids.
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U2 - 10.1103/PhysRevLett.120.247601
DO - 10.1103/PhysRevLett.120.247601
M3 - Article
C2 - 29957011
AN - SCOPUS:85048630347
VL - 120
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 24
M1 - 247601
ER -