Multipolar Kondo effect in a S01−P23 mixture of Yb173 atoms
| Autor: | Tetyana Kuzmenko, Yshai Avishai, Gyu-Boong Jo, Igor Kuzmenko |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Physics
Condensed matter physics Exchange interaction Renormalization group 01 natural sciences Magnetic susceptibility 010305 fluids & plasmas 0103 physical sciences Quadrupole Antiferromagnetism Condensed Matter::Strongly Correlated Electrons Kondo effect 010306 general physics Fermi gas Ground state |
| Zdroj: | Physical Review B. 97 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.97.075124 |
| Popis: | Whereas in the familiar Kondo effect the exchange interaction is dipolar, there are systems in which the exchange interaction is multipolar, as has been realized in a recent experiment. Here, we study multipolar Kondo effect in a Fermi gas of cold $^{173}\mathrm{Yb}$ atoms. Making use of different ac polarizabilities of the electronic ground state $\mathrm{Yb}(^{1}\mathrm{S}_{0})$ and the long-lived metastable state ${\mathrm{Yb}}^{*}(^{3}\mathrm{P}_{2})$, it is suggested that the latter atoms can be localized and serve as a dilute concentration of magnetic impurities while the former ones remain itinerant. The exchange mechanism between the itinerant Yb and the localized ${\mathrm{Yb}}^{*}$ atoms is analyzed and shown to be antiferromagnetic. The quadrupole and octupole interactions act to enhance the Kondo temperature ${T}_{K}$ that is found to be experimentally accessible. The bare exchange Hamiltonian needs to be decomposed into dipole $(\text{d})$, quadrupole $(\text{q})$, and octupole $(\text{o})$ interactions in order to retain its form under renormalization group (RG) analysis, in which the corresponding exchange constants $({\ensuremath{\lambda}}_{\text{d}},{\ensuremath{\lambda}}_{\text{q}}$, and ${\ensuremath{\lambda}}_{\text{o}})$ flow independently. Numerical solution of the RG scaling equations reveals a few finite fixed points. Arguments are presented that the Fermi-liquid fixed point at low temperature is unstable, indicating that the impurity is overscreened, which suggests a non-Fermi-liquid phase. The impurity contributions to the specific heat, entropy, and the magnetic susceptibility are calculated in the weak coupling regime $(T\ensuremath{\gg}{T}_{K})$, and are compared with the analogous results obtained for the standard case of dipolar exchange interaction (the $s\ensuremath{-}d$ Hamiltonian). |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|