报告题目：Oxygen Vacancy-Driven Orbital One- and Two-channel Kondo Effect in RuO2 and IrO2 Nanowires

报告人：林志忠 教授（台湾阳明交通大学）

报告时间：2024年11月25日（周一） 14：00-15：30

报告地点：北洋园校区49教410室

报告摘要：

      Strong electron correlations have long been recognized as driving the emergence of novel phases of matter. A well-recognized example is high-temperature superconductivity which cannot be understood in terms of the standard weak-coupling theory. The exotic properties accompanying the formation of the two-channel Kondo (2CK) effect including the emergence of an unconventional metallic state in the low-energy limit also originate from strong electron interactions. Despite its paradigmatic role in the formation of non-standard metal behavior, the stringent conditions required for its emergence have made the observation of the nonmagnetic, orbital 2CK effect in real quantum materials difficult, if not impossible. We report the observation of orbital one- and two-channel Kondo physics in the symmetry-enforced Dirac nodal line (DNL) metals IrO₂ and RuO₂ nanowires and show that the symmetries that enforce the existence of DNLs also promote the formation of nonmagnetic Kondo correlations. Rutile oxide nanostructures thus form a versatile quantum matter platform to engineer and explore intrinsic, interacting topological states of matter.

参考文献：

S. Kirchner, Advanced Quantum Technologies 3, 1900128 (2020).

S. S. Yeh, et al., Nature Communications 11, 4749 (2020).

林志忠、Stefan Kirchner《轨道双通道近藤效应》，《物理》杂志(近期刊登)。

报告人简介：

      林志忠教授于1979年在台湾交通大学电子物理系获得学士学位，1986年在美国普渡大学获得物理学博士学位，之后分别在密歇根大学和弗吉尼亚大学做博士后研究。他于1988年获聘为台湾大学物理系副教授，于1992年晋升为教授。自1997年以来，他一直在台湾（阳明）交通大学物理研究所和电子物理系任教。他的研究领域是低温凝聚态物理实验，聚焦于量子输运和电子退相干、近藤效应、低频噪声以及小型器件和异质结构中的非常规超导性质。