Non-Fermi liquids and quantum criticality in multipolar Kondo systems

          @misc{ pirsa_PIRSA:22110070,
            doi = {10.48660/22110070},
            url = {https://pirsa.org/22110070},
            author = {Kim, Yong-Baek},
            keywords = {Condensed Matter},
            language = {en},
            title = {Non-Fermi liquids and quantum criticality in multipolar Kondo systems},
            publisher = {Perimeter Institute},
            year = {2022},
            month = {nov},
            note = {PIRSA:22110070 see, \url{https://pirsa.org}}
          }
          

Abstract

We discuss emergent non-Fermi liquid behaviors in multipolar Kondo systems, where conduction electrons interact with the non-Kramers local moments carrying higher-rank multipolar moments such as quadrupolar and octupolar moments. We first show that unexpected non-Fermi liquid states arise in the single impurity multipolar Kondo system using the renormalization group and conformal field theory. Next, we study the competition between the Kondo and RKKY interactions in the Bose-Fermi Kondo systems, where the RKKY interaction between multipolar moments is represented by a bosonic degree of freedom. We present the renormalization group solution of this problem and describe the quantum critical behaviors. If time permits, we also discuss possible superconducting states arising from the multipolar Kondo interactions. We compare the theoretical results with existing experimental data on some cubic f-electron systems.