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Prof. Dr. Armando A. Aligia, Centro Atómico Bariloche – New results on the Kondo effect in systems with atoms and molecules on metallic surfaces – 15 de Julho 14:00

15 de julho:14:00 - 15:00


After a brief introduction to the Kondo effect, I will briefly explain the explanations so far that explain the presence of a peak or a dip in the differential conductance dI/dV near V=0 observed by STM. Recently, interpreting experiments for Co on Cu(111), in which an antiresonance in dI/dV at V=0 and a resonance near the bottom of the conduction band are observed, we conclude by NRG calculations that the STM tip “sees” mainly the Co s electrons and the dip is due to interference effects [1]. This is confirmed by recent ab initio calculations [2]. In addition, from other NRG calculations in a spin-1 two-channel Kondo model with anisotropy D(SZ)2 we find a topological quantum phase transition in which the Kondo peak is suddenly turned to a dip with increasing D [3]. For large D the system is in a “non-Landau” Fermi liquid phase not adiabatically connected to a non-interacting system. Extending the theory to non-equivalent orbitals and non-zero magnetic field we can explain several relevant experiments in Fe phthalocyanine [4].

[1] J. Fernández, P. Roura-Bas, and A. A. Aligia, Phys. Rev. Lett. 126, 046801 (2021)
[2] M. S. Tacca et al., arXiv:2103.12560.
[3] G. G. Blesio, L. O. Manuel, P. Roura-Bas, and A. A. Aligia, Phys. Rev. B 98, 195435 (2018), Phys. Rev. B 100, 075434 (2019)
[4] R. Zitko, G. G. Blesio, L. O. Manuel, and A. A. Aligia, ArXiv:2105.13248


15 de julho
14:00 - 15:00