美国乔治梅森大学Fereshte Ghahari团队通过熵敏测量检测了分数量子霍尔态。2025年3月17日出版的《自然—物理学》杂志发表了这项成果。

清洁二维电子系统的热功率与每个电荷载流子的熵成正比，可以探测到强烈相互作用的量子相，如分数量子霍尔液体。特别是，热功率是探测准粒子统计的一个有价值的参数，在某些偶数分母分数量子霍尔态中，准粒子统计会产生过量熵。

研究组证明分数量子霍尔态的磁热功率检测比电阻率测量更敏感。他们在伯纳堆叠的双层石墨烯的背景下这样做，并在相对较低的磁场下突出了几个偶数分母态。这些热电测量能力支持了人们对分数量子霍尔态的兴趣，以寻找具有非阿贝尔统计的准粒子，并将双层石墨烯提升为实现这一目标的有前景的平台。

附：英文原文

Title: Detection of fractional quantum Hall states by entropy-sensitive measurements

Author: Sultana, Nishat, Rienstra, Robert W., Watanabe, Kenji, Taniguchi, Takashi, Stroscio, Joseph A., Zhitenev, Nikolai B., Feldman, D. E., Ghahari, Fereshte

Issue&Volume: 2025-03-17

Abstract: The thermopower of a clean two-dimensional electron system is directly proportional to the entropy per charge carrier and can probe strongly interacting quantum phases such as fractional quantum Hall liquids. In particular, thermopower is a valuable parameter to probe the quasiparticle statistics that give rise to excess entropy in certain even-denominator fractional quantum Hall states. Here we demonstrate that the magneto-thermopower detection of fractional quantum Hall states is more sensitive than resistivity measurements. We do this in the context of Bernal-stacked bilayer graphene and highlight several even-denominator states at a relatively low magnetic field. These capabilities of thermopower measurements support the interest in fractional quantum Hall states for finding quasiparticles with non-Abelian statistics and elevate bilayer graphene as a promising platform for achieving this.

DOI: 10.1038/s41567-025-02813-z

Source: https://www.nature.com/articles/s41567-025-02813-z