Self-consistent theory of molecular switching
Self-consistent theory of molecular switching
复制标题
分子开关的自洽理论
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
I. Martin
中科院分区：
文献类型：
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作者：
F. Pistolesi;Y. Blanter;I. Martin
我们研究了由一个具有软振动自由度的分子耦合到金属引线的分子开关模型。在存在强电子-离子相互作用的情况下，分子的不同电荷状态对应于实质上不同的离子构型，这可导致在能量上接近的构型之间非常缓慢的切换（弗兰克-康登阻断）。然而，传输电压的应用可以驱使分子远离热平衡，从而显著加速开关。隧穿电子起到热浴的作用，其有效温度取决于所施加的传输电压。包括运输诱导的“加热”自洽，我们确定的静态的电流-电压特性的设备和对称和非对称设备的开关动力学。我们还研究了一个额外的耗散环境的影响，并证明它可以导致增强的非线性器件的输运特性，并显着抑制开关动态。
We study the model of a molecular switch comprised of a molecule with a soft vibrational degree of freedom coupled to metallic leads. In the presence of strong electron-ion interaction, different charge states of the molecule correspond to substantially different ionic configurations, which can lead to very slow switching between energetically close configurations (Franck-Condon blockade). Application of transport voltage, however, can drive the molecule far out of thermal equilibrium and thus dramatically accelerate the switching. The tunneling electrons play the role of a heat bath with an effective temperature dependent on the applied transport voltage. Including the transport induced “heating” self-consistently, we determine the stationary currentvoltage characteristics of the device and the switching dynamics for symmetric and asymmetric devices. We also study the effects of an extra dissipative environment and demonstrate that it can lead to enhanced nonlinearities in the transport properties of the device and dramatically suppress the switching dynamics.