Eder and Ohta have found a violation of the Luttinger rule in the spectral function for the ${t\ensuremath{-}t}^{\ensuremath{'}}\ensuremath{-}J$ model, which was interpreted as a possible breakdown of the Tomonaga-Luttinger (TL) description in models where electrons can pass each other. Here we have computed the spin correlation along with the spectral function for the one-dimensional ${t\ensuremath{-}t}^{\ensuremath{'}}$ Hubbard model and two-leg Hubbard ladder. By varying the Hubbard $U$ we have identified that such a phenomenon is in fact a spinless-fermion-like behavior of holes moving in a spiral spin configuration that has a spin correlation wavelength equal to the system size.Eder and Ohta have found a violation of the Luttinger rule in the spectral function for the ${t\ensuremath{-}t}^{\ensuremath{'}}\ensuremath{-}J$ model, which was interpreted as a possible breakdown of the Tomonaga-Luttinger (TL) description in models where electrons can pass each other. Here we have computed the spin correlation along with the spectral function for the one-dimensional ${t\ensuremath{-}t}^{\ensuremath{'}}$ Hubbard model and two-leg Hubbard ladder. By varying the Hubbard $U$ we have identified that such a phenomenon is in fact a spinless-fermion-like behavior of holes moving in a spiral spin configuration that has a spin correlation wavelength equal to the system size.

arXiv:cond-mat/9809084Physical review. B, Condensed matterNov 1, 19989 citations

Hubbard model on the triangular lattice using dynamical cluster approximation and dual fermion methods

Hunpyo Lee, Gang Li, H. Monien

We investigate the Hubbard model on the triangular lattice at half filling using the dynamical cluster approximation (DCA) and dual fermion (DF) methods in combination with continuous-time quantum Monte Carlo (CT QMC) and semiclassical approximation (SCA) methods. We study the one-particle properties and nearest-neighbor spin correlations using the DCA method. We calculate the spectral functions using the CT QMC and SCA methods. The spectral function in the SCA and obtained by analytic continuation of the Pad\'e approximation in CT QMC are in good agreement. We determine the metal-insulator transition and the hysteresis associated with a first-order transition in the double-occupancy and nearest-neighbor spin-correlation functions as functions of temperature. As a further check, we employ the DF method and discuss the advantages and limitation of the dynamical mean-field theory, DCA, and recently developed DF methods by comparing the Green's functions. We find an enhancement of antiferromagnetic correlations and provide evidence for magnetically ordered phases by calculating the spin susceptibility.We investigate the Hubbard model on the triangular lattice at half filling using the dynamical cluster approximation (DCA) and dual fermion (DF) methods in combination with continuous-time quantum Monte Carlo (CT QMC) and semiclassical approximation (SCA) methods. We study the one-particle properties and nearest-neighbor spin correlations using the DCA method. We calculate the spectral functions using the CT QMC and SCA methods. The spectral function in the SCA and obtained by analytic continuation of the Pad\'e approximation in CT QMC are in good agreement. We determine the metal-insulator transition and the hysteresis associated with a first-order transition in the double-occupancy and nearest-neighbor spin-correlation functions as functions of temperature. As a further check, we employ the DF method and discuss the advantages and limitation of the dynamical mean-field theory, DCA, and recently developed DF methods by comparing the Green's functions. We find an enhancement of antiferromagnetic correlations and provide evidence for magnetically ordered phases by calculating the spin susceptibility.

arXiv:0807.1683Physical Review BNov 24, 200846 citations

Spectral functions of the spinless Holstein model

Jan 1, 20050 citations

Dynamical correlation functions of a two-spin operator in quantum spin chains

Matheus Schossler, Rodrigo G. Pereira

Livro de ResumosJan 1, 20160 citations

Spectral functions of the one-dimensional Hubbard model in the U→+∞ limit:How to use the factorized wave function

Karlo Penc, K. Hallberg, Frédéric Mila +1 more

We give the details of the calculation of the spectral functions of the one-dimensional Hubbard model using the spin-charge factorized wave function for several versions of the U\ensuremath{\rightarrow}+\ensuremath{\infty} limit. The spectral functions are expressed as a convolution of charge and spin dynamical correlation functions. A procedure to evaluate these correlation functions very accurately for large systems is developed, and analytical results are presented for the low-energy region. These results are fully consistent with the conformal field theory. We also propose a direct method of extracting the exponents from the matrix elements in more general cases.We give the details of the calculation of the spectral functions of the one-dimensional Hubbard model using the spin-charge factorized wave function for several versions of the U\ensuremath{\rightarrow}+\ensuremath{\infty} limit. The spectral functions are expressed as a convolution of charge and spin dynamical correlation functions. A procedure to evaluate these correlation functions very accurately for large systems is developed, and analytical results are presented for the low-energy region. These results are fully consistent with the conformal field theory. We also propose a direct method of extracting the exponents from the matrix elements in more general cases.

arXiv:cond-mat/9701051Physical review. B, Condensed matterJun 15, 199791 citations

U

we have identified that such a phenomenon is in fact a spinless-fermion-like behavior of holes moving in a spiral spin configuration that has a spin correlation wavelength equal to the system size.