Berlin 2015 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 112: Correlated Electrons: (General) Theory 3

TT 112.6: Talk

Friday, March 20, 2015, 11:00–11:15, H 3010

What is the fate of the Mott metal-insulator transition in two dimensions? — •Thomas Schäfer¹, Faruk Geles², Daniel Rost^3,4, Georg Rohringer¹, Enrico Arrigoni², Karsten Held¹, Nils Blümer³, Markus Aichhorn², and Alessandro Toschi¹ — ¹Institute of Solid State Physics, Vienna University of Technology, 1040 Vienna, Austria — ²Institute of Theoretical and Computational Physics, Graz University of Technology, Graz, Austria — ³Institute of Physics, Johannes Gutenberg University, Mainz, Germany — ⁴Graduate School Materials Science in Mainz, Johannes Gutenberg University, Mainz, Germany

One of the most fundamental hallmarks of the physics of strong electronic correlations is, undoubtedly, the Mott-Hubbard metal-insulator transition (MIT), whose properties can be well captured in infinite dimensions. However, astonishingly little is known in the case of finite dimensions where spatial correlations become dominant. Our analysis of the two-dimensional Hubbard model on a square lattice demonstrates that at low temperatures the critical interaction for the onset of an insulator is progressively reduced towards zero by the inclusion of spatial correlations on longer and longer length scales. Eventually an insulating spectral gap is always opened at low-enough temperatures by (non-local) antiferromagnetic Slater paramagnons, so that the MIT completely disappears in this case [1].

[1] T. Schäfer, F. Geles, D. Rost, G. Rohringer, E. Arrigoni, K. Held,

N. Blümer, M. Aichhorn and A. Toschi, arXiv:1405.7250