The Linked Cluster Theory in the spin polaron formulation is investigated in this paper using the finite temperature (Matsubara) Green’s function method. We use a representation where holes and spins are described as spinless fermions and normal bosons, respectively. An analytic expression of the thermodynamic potential of high-temperature superconductors in the superconducting state was obtained using the Linked Cluster theory and an expression for its normal state by setting the energy gap to zero. The expression of the thermodynamic potential enabled us to calculate two bulk thermodynamic properties of high-temperature superconductors, entropy and specific heat, both in the normal and superconducting states.The Linked Cluster Theory in the spin polaron formulation is investigated in this paper using the finite temperature (Matsubara) Green’s function method. We use a representation where holes and spins are described as spinless fermions and normal bosons, respectively. An analytic expression of the thermodynamic potential of high-temperature superconductors in the superconducting state was obtained using the Linked Cluster theory and an expression for its normal state by setting the energy gap to zero. The expression of the thermodynamic potential enabled us to calculate two bulk thermodynamic properties of high-temperature superconductors, entropy and specific heat, both in the normal and superconducting states.

International Journal of Modern Physics BMar 7, 20191 citation

Importance of local correlations for the order parameter of high- Tc superconductors

M. Balzer, Werner R. Hanke, Michael Potthoff

It is shown that local temporal correlations in addition to nonlocal spatial correlations are important to understand the size and the doping dependence of the $d$ -wave superconducting order parameter of high-temperature superconductors. To this end, the hole- and electron-doped two-dimensional Hubbard model at zero temperature is considered and treated by an extension of the variational cluster approximation. Within this approach, the effects of temporal correlations can be studied systematically and in a thermodynamically consistent way by comparing results obtained from different reference clusters. Contact can be made with previous cellular (plaquette) dynamical mean-field calculations. This shows that temporal correlations considerably decrease the order parameter and provide a substantial gain of binding energy. Besides, a few methodical insights regarding real-space quantum-cluster approaches are obtained in addition.It is shown that local temporal correlations in addition to nonlocal spatial correlations are important to understand the size and the doping dependence of the $d$-wave superconducting order parameter of high-temperature superconductors. To this end, the hole- and electron-doped two-dimensional Hubbard model at zero temperature is considered and treated by an extension of the variational cluster approximation. Within this approach, the effects of temporal correlations can be studied systematically and in a thermodynamically consistent way by comparing results obtained from different reference clusters. Contact can be made with previous cellular (plaquette) dynamical mean-field calculations. This shows that temporal correlations considerably decrease the order parameter and provide a substantial gain of binding energy. Besides, a few methodical insights regarding real-space quantum-cluster approaches are obtained in addition.

arXiv:0912.1282Physical Review BApr 27, 20108 citations

Quantum critical behaviour in a high-Tc superconductor

D. van der Marel, H. J. A. Molegraaf, Jan Zaanen +7 more

arXiv:cond-mat/0309172NatureSep 1, 2003363 citations

It is shown that local temporal correlations in addition to nonlocal spatial correlations are important to understand the size and the doping dependence of the

d

-wave superconducting order parameter of high-temperature superconductors. To this end, the hole- and electron-doped two-dimensional Hubbard model at zero temperature is considered and treated by an extension of the variational cluster approximation. Within this approach, the effects of temporal correlations can be studied systematically and in a thermodynamically consistent way by comparing results obtained from different reference clusters. Contact can be made with previous cellular (plaquette) dynamical mean-field calculations. This shows that temporal correlations considerably decrease the order parameter and provide a substantial gain of binding energy. Besides, a few methodical insights regarding real-space quantum-cluster approaches are obtained in addition.