We present a novel approach for a systematic large-spin expansion of the t-J Hamiltonian which enables us to work without the constraint of no double occupancy. In our scheme we can perform the large-spin limit ensuring that the low energy spin excitations are in exact correspondence with the physical excitations of the s = 1/2 Hilbert space. As a consequence, we expect a smooth dependence of the physical quantities on the expansion parameter 1/s. As a first application of the method we study the case of a single hole in a Neel background. A systematic expansion in fluctuations about this stable solution indicates that by increasing t/J the quasiparticle weight strongly depends on the momentum carried by the hole. Results, obtained on small lattice sizes, are found in excellent agreement with exact diagonalization data.
http://hdl.handle.net/20.500.11767/13582
Titolo: | LARGE PHYSICAL SPIN APPROACH FOR STRONGLY CORRELATED ELECTRONS |
Autori: | ANGELUCCI A; SORELLA S; POIBLANC D |
Rivista: | |
Data di pubblicazione: | 1995 |
Volume: | 198 |
Fascicolo: | 2 |
Pagina iniziale: | 145 |
Pagina finale: | 150 |
Digital Object Identifier (DOI): | 10.1016/0375-9601(95)00006-O |
Appare nelle tipologie: | 1.1 Journal article |