论文标题
石墨烯中的HALL粘度和流体动力逆Nernst效应
Hall viscosity and hydrodynamic inverse Nernst effect in graphene
论文作者
论文摘要
由石墨烯片的霍尔粘度测量值激励,我们研究了外部电场和磁场中有限宽度通道中电子的流体动力传输。我们认为电荷密度从距离迪拉克(Dirac Point)到费米(Fermi)液体状态的电荷密度有所不同。我们发现了源自Hall viscous和Lorentz部队的流体动力大厅和反向的Nernst信号的两项相互贡献。这项竞争导致全部信号在磁场上的非线性依赖性,甚至在两个信号的不同临界场值下取消。特别是,费米液体状态中的流体动力逆Nernst信号主要由大厅粘性贡献。我们进一步表明,有限的通道宽度会导致洛伦兹比率的抑制,而磁场则提高了该比率。所有这些效果都是在实验中可访问的参数方案中预测的。
Motivated by Hall viscosity measurements in graphene sheets, we study hydrodynamic transport of electrons in a channel of finite width in external electric and magnetic fields. We consider electric charge densities varying from close to the Dirac point up to the Fermi liquid regime. We find two competing contributions to the hydrodynamic Hall and inverse Nernst signals that originate from the Hall viscous and Lorentz forces. This competition leads to a non-linear dependence of the full signals on the magnetic field and even a cancellation at different critical field values for both signals. In particular, the hydrodynamic inverse Nernst signal in the Fermi liquid regime is dominated by the Hall viscous contribution. We further show that a finite channel width leads to a suppression of the Lorenz ratio, while the magnetic field enhances this ratio. All of these effects are predicted in parameter regimes accessible in experiments.