论文标题
无分散电子带中的量子传输
Quantum transport in dispersionless electronic bands
论文作者
论文摘要
平坦的电子带是违反直觉的：随着电子速度消失，我们的常规准颗粒传输概念不再有效。我们在这里研究了完全平坦的频带的广义家族中的量子传输[PRB 105，L241102（2022）]，发现尽管常规贡献确实消失了，但量子几何贡献贡献会增加了增强的电子传输。该贡献与完美平坦的频带中的轨道轨道量化相连，仅适用于几何界频带（例如，平面切尔带）。我们发现平面带中的导热电导，热电响应和超流量重量的表达式相似。特别是，我们报告了与平坦拓扑带相关的异常热电器，其值达到$ \ frac {k_b} {e} \ ln 2 $$ \ $ 60 $μ$ v/k，量子的量子单位，这是常规分散频带中预期的。
Flat electronic bands are counterintuitive: with the electron velocity vanishing, our conventional notions of quasiparticle transport are no longer valid. We here study the quantum transport in the generalized families of perfectly flat bands [PRB 105, L241102 (2022)], and find that while the conventional contributions indeed vanish, the quantum-geometric contribution gives rise to the enhanced electronic transport. This contribution is connected to the Wannier orbital quantization in the perfectly flat bands, and is present only for geometrically-nontrivial bands (for example, flat Chern bands). We find similar expressions for thermal conductance, thermoelectric response, and superfluid weight in the flat bands. In particular, we report the anomalous thermopower associated with flat topological bands reaching values as large as $\frac{k_B}{e}\ln 2$$\approx$60 $μ$V/k, the quantum unit of thermopower, not expected in conventional dispersive bands.
