scholarly journals Simultaneous Control of Bandfilling and Bandwidth in Electric Double-Layer Transistor Based on Organic Mott Insulator κ-(BEDT-TTF)2Cu[N(CN)2]Cl

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 42
Author(s):  
Yoshitaka Kawasugi ◽  
Hiroshi M. Yamamoto

The physics of quantum many-body systems have been studied using bulk correlated materials, and recently, moiré superlattices formed by atomic bilayers have appeared as a novel platform in which the carrier concentration and the band structures are highly tunable. In this brief review, we introduce an intermediate platform between those systems, namely, a band-filling- and bandwidth-tunable electric double-layer transistor based on a real organic Mott insulator κ-(BEDT-TTF)2Cu[N(CN)2]Cl. In the proximity of the bandwidth-control Mott transition at half filling, both electron and hole doping induced superconductivity (with almost identical transition temperatures) in the same sample. The normal state under electric double-layer doping exhibited non-Fermi liquid behaviors as in many correlated materials. The doping levels for the superconductivity and the non-Fermi liquid behaviors were highly doping-asymmetric. Model calculations based on the anisotropic triangular lattice explained many phenomena and the doping asymmetry, implying the importance of the noninteracting band structure (particularly the flat part of the band).

2014 ◽  
Vol 111 (11) ◽  
pp. 3979-3983 ◽  
Author(s):  
T. Katase ◽  
H. Hiramatsu ◽  
T. Kamiya ◽  
H. Hosono

2003 ◽  
Vol 17 (28) ◽  
pp. 4947-4952
Author(s):  
A. J. LEGGETT ◽  
E. KROTSCHECK ◽  
J. W. NEGELE

The Eighth Eugene Feenberg Medal is awarded to Philippe Nozières in recognition of his many pathbreaking contributions to many-body theory, including • His definitive work on the properties of the free electron gas, in particular in the region of realistic metallic densities, • his rigorous development of the theory of a normal Fermi liquid, which provided a firm microscopic foundation for the Landau theory, • his analysis of the nonequilibrium thermodynamics of 3-He solid-liquid mixtures, • his exact solution to the X-ray edge problem, • his elegant formulation of the low-temperature solution to the single-channel Kondo problem in the language of Fermi-liquid theory, • his introduction of the many-channel problem as a new class of quantum impurity systems, and • his innovative work on the static and dynamic behavior of the liquid-solid interface.


Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 791
Author(s):  
Yoshitaka Kawasugi ◽  
Hikaru Masuda ◽  
Jiang Pu ◽  
Taishi Takenobu ◽  
Hiroshi M. Yamamoto ◽  
...  

Field-effect transistors based on strongly correlated insulators are an excellent platform for studying the electronic phase transition and simultaneously developing phase transition transistors. Molecular conductors are suitable for phase transition transistors owing to the high tunability of the electronic states. Molecular Mott transistors show field-induced phase transitions including superconducting transitions. However, their application to charge-ordered insulators is limited. In this study, we fabricated electric double layer transistors based on quarter-filled charge-ordered insulators α-(BEDT-TTF)2I3 and α-(BETS)2I3. We observed ambipolar field effects in both compounds where both electron and hole doping (up to the order of 1013 cm−2) reduces the resistance by the band filling shift from the commensurate value. The maximum field-effect mobilities are approximately 10 and 55 cm2/Vs, and the gate-induced conductivities are 0.96 and 3.6 e2/h in α-(BEDT-TTF)2I3 and α-(BETS)2I3, respectively. However, gate-induced metallic conduction does not emerge. The gate voltage dependence of the activation energy in α-(BEDT-TTF)2I3 and the Hall resistance in α-(BETS)2I3 imply that the electric double layer doping in the present experimental setup induces hopping transport rather than band-like two-dimensional transport.


2014 ◽  
Vol 134 (5) ◽  
pp. 360-361
Author(s):  
Masumi Fukuma ◽  
Takayuki Uchida ◽  
Yukito Fukushima ◽  
Jinichi Ogawa ◽  
Katsumi Yoshino

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