IBM T.J. Watson Research Center, Yorktown Heights, New York 10598, USA.
Phys Rev Lett. 2012 Dec 7;109(23):236604. doi: 10.1103/PhysRevLett.109.236604. Epub 2012 Dec 5.
Conduction between graphene layers is suppressed by momentum conservation whenever the layer stacking has a rotation. Here we show that phonon scattering plays a crucial role in facilitating interlayer conduction. The resulting dependence on orientation is radically different than previously expected, and far more favorable for device applications. At low temperatures, we predict diode-like current-voltage characteristics due to a phonon bottleneck. Simple scaling relationships give a good description of the conductance as a function of temperature, doping, rotation angle, and bias voltage, reflecting the dominant role of the interlayer beating phonon mode.
当层堆叠有旋转时，石墨烯层之间的传导会受到动量守恒的抑制。在这里，我们表明声子散射在促进层间传导方面起着至关重要的作用。由此产生的对取向的依赖性与之前的预期完全不同，并且对器件应用更为有利。在低温下，由于声子瓶颈，我们预测了类似二极管的电流-电压特性。简单的比例关系很好地描述了温度、掺杂、旋转角度和偏置电压作为函数的电导，反映了层间拍频声子模式的主导作用。
