Seminarium Oddziału Badań Magnetyków
Microsoft Teams
Kondo-stabilized spin-liquid phase of two impurities
Dr Krzysztof Wójcik
Institute of Molecular Physics, Polish Academy of Sciences, Poznań
Seminarium odbędzie się zdalnie w aplikacji Microsoft Teams. W celu wzięcia udziału w wydarzeniu należy dołączyć do zespołu Seminarium OBM.Można do niego dołączyć na stałe przy użyciu kodu dostępu ol7omod (dotyczy to osób posiadających konto w domenie intibs.pl, pozostałe osoby proszę o kontakt z prof. dr. hab. Piotrem Wiśniewskim ()).
Streszczenie:
The phase diagram of the conventional 2-impurity Kondo model and its relevance to correlated lattice models have been a subject of a long debate. It is now clear that it features a quantum phase transition (QPT) between the Kondo and the RKKY phase only in the model extended with a specially designed counter-term. I will present results obtained for a different extension of the standard 2-impurity model, where each of the impurities is coupled to a different host, and the hosts (not impurities) are directly coupled by spin-spin exchange. The model exhibits Jones-Varma QPT even away from the particle-hole symmetry point. Moreover, a second QPT occurs upon tuning the same inter-host coupling to very high values, where the system forms 2-impurity version of a spin-liquid. I will discuss the possibilities for realization of this scenario in quantum-dot structures and heavy-fermion materials.
