Berlin 2015 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 71: Correlated Electrons: Poster Session
TT 71.73: Poster
Mittwoch, 18. März 2015, 15:00–18:00, Poster B
Single-Particle Green’s Function from the time-dependent Gutzwiller Approximation — •Konstantin Hobuß, Jörg Bünemann, and Florian Gebhard — Universität Marburg, Fachbereich Physik, Renthof 6, 35037 Marburg
We calculate the single-particle Green’s function of the single-band Hubbard model from the time-dependent Gutzwiller Approximation within a Lagrange formalism [1]. In our approach, we add an electron with fixed wave vector k→ which can be interpreted as a small perturbation of the system. The Euler-Lagrange equations yield the dynamics of the corresponding variational parameters caused by the small perturbation. For the special case of a half-filled paramagnetic ground state, we find oscillations of the double occupancy with a frequency Ω2 = 16 ε02 ( 1 − u2 ) where u=U/UBR is the interaction strength in terms of the Brinkman-Rice energy and ε0 is the energy per site of the noninteracting system. From the dynamics of the variational parameters, we can compute the single-particle Green’s function for all frequencies. At small excitation energies, we recover previous results for the Gutzwiller quasi-particle dispersion [2].
[1] J. Bünemann et. al., New J. Phys. 15 (2013), 053050.
[2] J. Bünemann et. al., Phys. Rev. B 67 (2003), 075103.