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| | 51 year old Precision Instrument Maker and Repairer Ty Leif from Port Hope, usually spends time with interests for instance geocaching, ganhando dinheiro na internet and fashion. Has toured ever since childhood and has been to numerous destinations, for instance Saltaire.<br><br>Visit my web-site: [http://comoganhardinheiro.comoganhardinheiro101.com ganhe dinheiro] |
| The '''t-J model''' was first derived in 1977 from the [[Hubbard model]] by [[Józef Spałek]]. The model describes strongly correlated electron systems. It is used to calculate [[high temperature superconductivity]] states in doped antiferromagnets.
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| The t-J [[Hamiltonian (quantum mechanics)|Hamiltonian]] is:
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| <math>\hat H = -t\sum_{<ij>\sigma}\left(\hat a^\dagger_{i\sigma} \hat a_{j\sigma} + \hat a^\dagger_{j\sigma} \hat a_{i\sigma}\right)
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| +
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| J\sum_{<ij>}(\vec S_{i}\cdot \vec S_{j}-n_in_j/4)
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| </math>
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| where
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| *<math>\sum_{<ij>}</math> - sum over nearest-neighbor sites i and j,
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| *<math>\hat a^\dagger_{i\sigma} , \hat a_{j\sigma}</math> - fermionic creation and annihilation operators,
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| *<math>\sigma</math> - spin polarization,
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| *<math>t</math> - hopping integral
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| *<math>J</math> - coupling constant <math>J = 4t^2/U</math>,
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| *<math>U</math> - coulomb repulsion,
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| *<math>n_{i} = \sum_{\sigma}\hat a^\dagger_{i\sigma}\hat a_{i\sigma}</math> - particle number at the site i, and
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| *<math> \vec S_i, \vec S_j </math> - spins on the sites i and j.
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| ==References==
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| * t-J model then and now: A personal perspective from the pioneering times, [[Józef Spałek]], [http://arxiv.org/abs/0706.4236 arXiv:0706.4236]
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| [[Category:Quantum mechanics]]
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| [[Category:Lattice models]]
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| [[Category:Condensed matter physics]]
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| {{physics-stub}}
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51 year old Precision Instrument Maker and Repairer Ty Leif from Port Hope, usually spends time with interests for instance geocaching, ganhando dinheiro na internet and fashion. Has toured ever since childhood and has been to numerous destinations, for instance Saltaire.
Visit my web-site: ganhe dinheiro