Kawasugi Yoshitaka, Yamamoto Hiroshi M, Tajima Naoya, Fukunaga Takeo, Tsukagoshi Kazuhito, Kato Reizo
Saitama University, Saitama, Saitama 338-8570, Japan.
Phys Rev Lett. 2009 Sep 11;103(11):116801. doi: 10.1103/PhysRevLett.103.116801. Epub 2009 Sep 8.
We report the influence of the field effect on the dc resistance and Hall coefficient in the strain-induced Mott insulating state of an organic superconductor kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Br. Conductivity obeys the formula for an activated transport sigma(square)=sigma(0)exp(-W/k(B)T), where sigma(0) is a constant and W depends on the gate voltage. The gate-voltage dependence of the Hall coefficient shows that, unlike in conventional field-effect transistors, the effective mobility of dense hole carriers ( approximately 1.6x10(14) cm(-2)) is enhanced by a positive gate voltage. This implies that carrier doping involves delocalization of intrinsic carriers that were initially localized due to electron correlation.
我们报道了场效应对有机超导体κ-(BEDT-TTF)₂Cu[N(CN)₂]Br的应变诱导莫特绝缘态下直流电阻和霍尔系数的影响。电导率服从激活输运公式σ(□)=σ₀exp(-W/k₈T)，其中σ₀为常数，W取决于栅极电压。霍尔系数对栅极电压的依赖性表明，与传统场效应晶体管不同，正栅极电压会增强密集空穴载流子的有效迁移率（约1.6×10¹⁴ cm⁻²）。这意味着载流子掺杂涉及到最初因电子关联而局域化的本征载流子的离域化。
