We study the thermodynamics of the two-dimensional Hubbard model within the dynamical cluster approximation. We use continuous time quantum Monte Carlo as a cluster solver to avoid the systematic error which complicates the calculation of the entropy and potential energy (double occupancy). We find that at a critical filling, there is a pronounced peak in the entropy divided by temperature, S/T, and in the normalized double occupancy as a function of doping. At this filling, we find that specific heat divided by temperature, C/T, increases strongly with decreasing temperature and kinetic and potential energies vary like T2 lnT. These are all characteristics of quantum critical behavior. © 2009 The American Physical Society.
Publication Source (Journal or Book title)
Physical Review B - Condensed Matter and Materials Physics
Mikelsons, K., Khatami, E., Galanakis, D., MacRidin, A., Moreno, J., & Jarrell, M. (2009). Thermodynamics of the quantum critical point at finite doping in the two-dimensional Hubbard model studied via the dynamical cluster approximation. Physical Review B - Condensed Matter and Materials Physics, 80 (14) https://doi.org/10.1103/PhysRevB.80.140505