0000000000129213

AUTHOR

Gerardo Sica

showing 3 related works from this author

Exact solution of the 1D Hubbard model in the atomic limit with inter-site magnetic coupling

2012

In this paper we present for the first time the exact solution in the narrow-band limit of the 1D extended Hubbard model with nearest-neighbour spin-spin interactions described by an exchange constant J. An external magnetic field h is also taken into account. This result has been obtained in the framework of the Green's functions formalism, using the Composite Operator Method. By means of this theoretical background, we have studied some relevant features such as double occupancy, magnetization, spin-spin and charge-charge correlation functions and derived a phase diagram for both ferro (J>0) and anti-ferro (J<0) coupling in the limit of zero temperature. We also report a study on de…

PhysicsStrongly Correlated Electrons (cond-mat.str-el)Statistical Mechanics (cond-mat.stat-mech)Specific heatCondensed matter physicsHubbard modelFOS: Physical sciencesCondensed Matter PhysicsInductive couplingElectronic Optical and Magnetic MaterialsMagnetic fieldCondensed Matter - Other Condensed MatterCondensed Matter - Strongly Correlated ElectronsMagnetizationExact solutions in general relativityDensity of statesCondensed Matter::Strongly Correlated ElectronsCondensed Matter - Statistical MechanicsOther Condensed Matter (cond-mat.other)Phase diagramThe European Physical Journal B
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Exact solution of the 1D Hubbard model with NN and NNN interactions in the narrow-band limit

2013

We present the exact solution, obtained by means of the Transfer Matrix (TM) method, of the 1D Hubbard model with nearest-neighbor (NN) and next-nearest-neighbor (NNN) Coulomb interactions in the atomic limit (t=0). The competition among the interactions ($U$, $V_1$, and $V_2$) generates a plethora of T=0 phases in the whole range of fillings. $U$, $V_1$, and $V_2$ are the intensities of the local, NN and NNN interactions, respectively. We report the T=0 phase diagram, in which the phases are classified according to the behavior of the principal correlation functions, and reconstruct a representative electronic configuration for each phase. In order to do that, we make an analytic limit $T\…

PhysicsStrongly Correlated Electrons (cond-mat.str-el)Statistical Mechanics (cond-mat.stat-mech)Hubbard modelFOS: Physical sciencesCondensed Matter PhysicsTransfer matrixElectronic Optical and Magnetic MaterialsCondensed Matter - Strongly Correlated ElectronsExact solutions in general relativityQuantum mechanicsCoulombLimit (mathematics)Electron configurationGround stateCondensed Matter - Statistical MechanicsPhase diagramThe European Physical Journal B
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Spin and charge orderings in the atomic limit of the U-V-J model

2011

In this paper we study a generalization of the 1D Hubbard model by considering density-density and Ising-type spin-spin nearest neighbor (NN) interactions, parameterized by $V$ and $J$, respectively. We present the T=0 phase diagram for both ferro ($J>0$) and anti-ferro ($J<0$) coupling obtained in the narrow-band limit by means of an extension to zero-temperature of the transfer-matrix method. Based on the values of the Hamiltonian parameters, we identify a number of phases that involve orderings of the double occupancy, NN density and spin correlations, being these latter very fragile.

PhysicsHistoryHubbard modelStrongly Correlated Electrons (cond-mat.str-el)Condensed Matter - SuperconductivityParameterized complexityFOS: Physical sciencesComputer Science ApplicationsEducationk-nearest neighbors algorithmSuperconductivity (cond-mat.supr-con)symbols.namesakeCondensed Matter - Strongly Correlated ElectronssymbolsCondensed Matter::Strongly Correlated ElectronsHamiltonian (quantum mechanics)Mathematical physicsPhase diagram
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