The magnetotransport properties of massless Dirac fermions in a gapless HgTe quantum well are investigated. In samples with narrow channels, a large negative magnetoresistance with a Lorentzian profile is observed, which is interpreted as a manifestation of electron viscosity due to an electron-electron interaction. A comparison of experiment with theory yields the shear stress relaxation time of the Dirac fermions caused by electron-electron scattering.

中文翻译：

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无质量狄拉克费米子的磁流体动力学和电子-电子相互作用

研究了无间隙 HgTe 量子阱中无质量狄拉克费米子的磁传输特性。在具有窄通道的样品中，观察到具有洛伦兹分布的大负磁阻，这被解释为由于电子-电子相互作用引起的电子粘性的表现。实验与理论的比较得出由电子-电子散射引起的狄拉克费米子的剪切应力弛豫时间。