Abstract
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.
| Original language | English |
|---|---|
| Article number | 247601 |
| Journal | Physical Review Letters |
| Volume | 120 |
| Issue number | 24 |
| DOIs | |
| Publication status | Published - Jun 14 2018 |
ASJC Scopus subject areas
- Physics and Astronomy(all)
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Evidence for Electronically Driven Ferroelectricity in a Strongly Correlated Dimerized BEDT-TTF Molecular Conductor. / Gati, Elena; Fischer, Jonas K.H.; Lunkenheimer, Peter; Zielke, David; Köhler, Sebastian; Kolb, Felizitas; Von Nidda, Hans Albrecht Krug; Winter, Stephen M.; Schubert, Harald; Schlueter, John A.; Jeschke, Harald Olaf; Valentí, Roser; Lang, Michael.
In: Physical Review Letters, Vol. 120, No. 24, 247601, 14.06.2018.Research output: Contribution to journal › Article › peer-review
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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: Clear evidence is provided for an order-disorder type ferroelectric state in dimerized κ - ( ET ) 2 Hg ( SCN ) 2 Cl [42] , driven by charge order within the ( ET ) 2 dimers and stabilized by a coupling to the anions. According to our ab initio density functional theory calculations, this material is characterized by a moderate strength of dimerization t 1 / t ′ ∼ 3 . Our results highlight the role of intradimer degrees of freedom in dimerized ( ET ) 2 X materials in promoting intriguing states. Besides the possibility for electronically driven multiferroicity, for the present material, we propose that the charge order in the presence of a strong frustration may induce a quasi-1D spin-liquid state as a consequence of dimensional reduction. 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. [1] 1 N. Ikeda , H. Ohsumi , K. Ohwada , K. Ishii , T. Inami , K. Kakurai , Y. Murakami , K. Yoshii , S. Mori , Y. Horibe , Nature (London) 436 , 1136 ( 2005 ). NATUAS 0028-0836 10.1038/nature04039 [2] 2 J. van den Brink and D. I. Khomskii , J. Phys. Condens. Matter 20 , 434217 ( 2008 ). JCOMEL 0953-8984 10.1088/0953-8984/20/43/434217 [3] 3 K. Yamamoto , A. A. Kowalska , and K. Yakushi , Appl. Phys. Lett. 96 , 122901 ( 2010 ). APPLAB 0003-6951 10.1063/1.3327810 [4] 4 M. Naka and S. Ishihara , J. Phys. Soc. Jpn. 79 , 063707 ( 2010 ). JUPSAU 0031-9015 10.1143/JPSJ.79.063707 [5] 5 S. Ishihara , J. Phys. Soc. Jpn. 79 , 011010 ( 2010 ). JUPSAU 0031-9015 10.1143/JPSJ.79.011010 [6] 6 J. M. Tranquada , B. J. Sternlieb , J. 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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 -