Berlin 2024 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
TT: Fachverband Tiefe Temperaturen
TT 91: 2D Materials VII: Heterostructures (joint session O/TT)
TT 91.7: Talk
Friday, March 22, 2024, 12:00–12:15, MA 005
Probing the phase transition to a coherent 2D kondo lattice — •Cosme Gonzalez Ayani1,2,3, Michele Pisarra4, Ivan M. Ibarburu2,3, Manuela Garnica2, Rodolfo Miranda2,3,5, Fabian Calleja2, Fernando Martin2,3, and Amadeo L. Vazquez de Parga2,3,5 — 1Institute of Physics, Zagreb, Croatia — 2Universidad autonoma madrid, Madrid, Spain — 3Imdea Nanociencia, Madrid, Spain — 4Universita della Calabria, Rende, Italy — 5IFIMAC, Madrid, Spain
Kondo screening occurs when a magnetic impurity is embedded in a metal, below a given temperature, known as the Kondo temperature, a singlet state forms between the spin of the impurity and the spins of the conduction electrons. When the distance between the magnetic impurities is small enough the physics of the system is expected to be modified. The first experimental evidence was obtained in the 1970s in systems containing rare earths. By means of scanning tunneling microscopy (STM) and spectroscopy (STS) at low temperatures we explore a van der Waals heterostructure consisting in a single layer of 1T-TaS2 on a 2H-TaS2 crystal. The 1T-TaS2 layer presents a (13x13)R13.9 charge density wave (CDW) with a localized electron at the center of every unit cell of the CDW. For temperatures below 28 K the spatially resolved STS shows the presence of a Kondo resonance in the Mott-Hubbard gap. For temperatures below 11 K the system develops a quantum coherent state called Kondo lattice, resembling the physics of 3D heavy fermion metals.
Keywords: 2D materials; TaS2 heterostructures; Kondo lattice; Low temperature; STM and STS