Huynh William, Liu Boliang, Munyan Simon, Ahadi Sina, Stemmer Susanne
Department of Physics, University of California, Santa Barbara, CA 93106, USA.
Materials Department, University of California, Santa Barbara, CA 93106-5050, USA.
Sci Adv. 2025 Sep 5;11(36):eady9006. doi: 10.1126/sciadv.ady9006.
Thermoelectric responses in two-dimensional electron gases subjected to magnetic fields have the potential to provide unique information about quasiparticle statistics. In this study, we show that chiral edge states play a key role in thermoelectric Hall bar measurements by completely controlling the direction of the internal thermal gradient. To this end, we perform measurements of the magnetothermoelectric responses of cadmium arsenide quantum wells. The magnetothermoelectric responses in the quantum Hall regime agree with theoretical predictions if one considers the role of chiral edge states, which flow in opposite directions on either side of the Hall bar and establish an internal temperature gradient that is perpendicular to the externally applied thermal gradient. We show that the results are self-consistent within this picture under different measurement conditions. We discuss potential applications of the findings, such as in nanoscale control of local temperature gradients and thermoelectric effects along with the characterization of other topological systems with chiral edges states.
处于磁场中的二维电子气的热电响应有潜力提供有关准粒子统计的独特信息。在本研究中，我们表明手性边缘态在热霍尔条测量中起着关键作用，它通过完全控制内部热梯度的方向来实现。为此，我们对砷化镉量子阱的磁热电响应进行了测量。如果考虑到手性边缘态的作用，量子霍尔 regime 中的磁热电响应与理论预测相符，手性边缘态在霍尔条两侧沿相反方向流动，并建立一个与外部施加的热梯度垂直的内部温度梯度。我们表明，在不同测量条件下，此图景中的结果是自洽的。我们讨论了这些发现的潜在应用，例如在局部温度梯度的纳米级控制和热电效应方面，以及对具有手性边缘态的其他拓扑系统的表征。
