The ground-state energy of rings with 10 or 16 sites and 2 or 4 fermions (holes or electrons) is computed as a function of the flux ? created by a vector potential constant along the ring (Aharonov-Bohm setup) for three different model Hamiltonians: the attractive (U<0) and repulsive (U>0) Hubbard and a t-J-like Hamiltonian. In all cases the flux is found to be quantized in units hc/2e, showing that the charge carriers are pairs. The possible role of phonon fluctuations in discriminating among the different models is also investigated.
Flux quantization in rings for Hubbard (attractive and repulsive) and t-J-like Hamiltonians
A Ferretti;A Lami
1992
Abstract
The ground-state energy of rings with 10 or 16 sites and 2 or 4 fermions (holes or electrons) is computed as a function of the flux ? created by a vector potential constant along the ring (Aharonov-Bohm setup) for three different model Hamiltonians: the attractive (U<0) and repulsive (U>0) Hubbard and a t-J-like Hamiltonian. In all cases the flux is found to be quantized in units hc/2e, showing that the charge carriers are pairs. The possible role of phonon fluctuations in discriminating among the different models is also investigated.File in questo prodotto:
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