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TT: Fachverband Tiefe Temperaturen

TT 9: CE: (General) Theory 1

TT 9.13: Talk

Monday, March 14, 2011, 17:30–17:45, HSZ 201

Tunnelling matrix elements with Gutzwiller wave functions — •Andrea Di Ciolo, Luca F. Tocchio, and Claudius Gros — Institut fuer Theoretische Physik, Goethe Universitaet Frankfurt, Frankfurt Am Main, Germany.

We use a generalized Gutzwiller approach [N. Fukushima, et al., Phys. Rev. B 72, 144505 (2005)], in order to study projected particle (hole) excitations for superconducting systems and systems with antiferromagnetic (AFM) order. As in the standard Gutzwiller scheme [M. C. Gutzwiller, Phys. Rev. Lett. 10, 159 (1963); F. C. Zhang, et al., Supercond. Sci. Tech. 1, 36 (1988)] the effects of the strong electronic correlations are given via the suppression of the site double occupancy; for our computations it is helpful to consider a lattice with a reservoir site unaffected by this suppression of the double occupancy.

In this approach we obtain the probabilities for the tunnelling of a particle (hole) into the projected state [A. Di Ciolo, et al., arXiv:1010.5055] . Our results are due only to the physical properties of the trial state and not to the choice of a specifical Hamiltonian: in this sense, they are model-independent but not universal, because they rely on the features of the chosen Gutzwiller wave function (projected Fermi Sea, BCS superconductor, AFM...)

The accuracy and the reliability of our analytical approximation is tested using the Variational Monte Carlo. Possible comparisons with tunnelling experiments will be discussed.