Vacancy-driven strange metal physics in transition metal rutile nanostructures
Institute of Physics and Department of Electrophysics, National Chiao Tung University, Taiwan
Metal physics beyond the Landau Fermi liquid paradigm is a central topic in contemporary condensed matter science. Its connection with unconventional superconductivity is experimentally well established but the conditions under which these enigmatic metals can form has remained perplexing. The routes proposed towards strange metal formation, which includes the two-channel Kondo effect, generally require rather special conditions or fine tuning. Here we report the observation of robust vacancy-driven orbital two-channel Kondo behavior which occurs without fine-tuning, in paramagnetic IrO2 nanowires possessing the rutile structure. We further demonstrate tunability of this unconventional state to its Fermi-liquid counterpart within the rutile structure through a complementary analysis of antiferromagnetic RuO2 nanowires. Our findings establish the inherent occurrence of non-Fermi liquid physics in a class of topological quantum materials, with implications for fundamental research and potential quantum device applications .
 S. S. Yeh, T. K. Su, A. S. Lien, F. Zamani, J. Kroha, C. C. Liao, S. Kirchner, and J. J. Lin, to be published.
Professor Juhn-Jong Lin received his BS degree in Electrophysics from National Chiao Tung University (Taiwan) in 1979, and PhD degree in Physics from Purdue University (USA) in 1986. He was a postdoctoral research fellow at University of Michigan–Ann Arbor (1986–1987) and University of Virginia at Charlottesville (1987–1988). He became an Associate Professor in Department of Physics at National Taiwan University in 1988, and a full professor in 1992. He has joined the Institute of Physics and Department of Electrophysics at National Chiao Tung University since 1997.
Professor Lin’s research area focuses on experimental low-temperature condensed matter physics. He is interested in quantum transport and electron dephasing, mesoscopic physics, Kondo physics, and dynamic defects in solids.