Berlin 2015 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 56: Correlated Electrons: Quantum-Critical Phenomena – Theory

TT 56.5: Vortrag

Mittwoch, 18. März 2015, 10:30–10:45, A 053

Dimensionless ratios at the honeycomb Hubbard model critical point — •Thomas C. Lang¹ and Ribhu K. Kaul² — ¹Boston University, Boston, USA — ²University of Kentucky, Lexington, USA

We study the nature and location of the phase transition between the semi-metal and Mott insulating antiferromagnetic state in the half-filled Hubbard model on the honeycomb. Using unbiased quantum Monte Carlo simulations, we measure dimensionless fermionic correlation and magnetic ratios, which provide precise and independent estimates for the couplings at which a mass gap opens in the single particle spectrum and at which the magnetic order sets in. An analysis of our data provides evidence for a direct continuous critical point between the semi-metal and the antiferromagnet, and an accurate window for the critical coupling, which does not include any of the previous estimates for the onset of magnetic order.