To shed light into the pairing mechanism of possible spin triplet superconductors ${(\text{TMTSF})}_{2}X$ and ${\text{Sr}}_{2}{\text{RuO}}_{4}$ , we study the competition among various spin singlet and triplet pairing channels in the Hubbard model by calculating the pairing interaction vertex using the ground state quantum Monte Carlo technique. We model ${(\text{TMTSF})}_{2}X$ by a quarter-filled quasi-one-dimensional (quasi-1D) Hubbard model, and the $\ensuremath{\gamma}$ band of ${\text{Sr}}_{2}{\text{RuO}}_{4}$ by a two-dimensional (2D) Hubbard model with a band filling of $\ensuremath{\sim}4∕3$. For the quasi-1D system, we find that triplet $f$ -wave pairing not only dominates over the triplet $p$ wave in agreement with the spin fluctuation theory, but also looks unexpectedly competitive against $d$ waves. For the 2D system, although the results suggest the presence of an attractive interaction in the triplet pairing channels, the $d$ -wave pairing interaction is found to be larger than those of the triplet channels.To shed light into the pairing mechanism of possible spin triplet superconductors ${(\text{TMTSF})}_{2}X$ and ${\text{Sr}}_{2}{\text{RuO}}_{4}$, we study the competition among various spin singlet and triplet pairing channels in the Hubbard model by calculating the pairing interaction vertex using the ground state quantum Monte Carlo technique. We model ${(\text{TMTSF})}_{2}X$ by a quarter-filled quasi-one-dimensional (quasi-1D) Hubbard model, and the $\ensuremath{\gamma}$ band of ${\text{Sr}}_{2}{\text{RuO}}_{4}$ by a two-dimensional (2D) Hubbard model with a band filling of $\ensuremath{\sim}4∕3$. For the quasi-1D system, we find that triplet $f$-wave pairing not only dominates over the triplet $p$ wave in agreement with the spin fluctuation theory, but also looks unexpectedly competitive against $d$ waves. For the 2D system, although the results suggest the presence of an attractive interaction in the triplet pairing channels, the $d$-wave pairing interaction is found to be larger than those of the triplet channels.

arXiv:cond-mat/0307553Physical Review BJun 18, 200431 citations

Spin-fluctuation mediated interaction in the two-dimensional Hubbard model

N. Bulut, Douglas J. Scalapino, Steven R. White

Physica C SuperconductivityMay 1, 199511 citations

Manifestations of spin and charge fluctuations in spectra of the Hubbard model

A. Sherman

The influence of long-range spin and charge fluctuations on spectra of the two-dimensional (2D) fermionic Hubbard model is considered using the strong coupling diagram technique (SCDT). Infinite sequences of diagrams containing ladder inserts, which describe the interaction of electrons with these fluctuations, are summed, and obtained equations are self-consistently solved for the range of Hubbard repulsions 4t [Formula: see text]U [Formula: see text] 8t and temperatures 0.3t [Formula: see text] T [Formula: see text] t with t the intersite hopping constant. It was found that a metal–insulator transition curve goes from larger U and T to smaller values of these parameters. The temperature decrease causes the transition to the long-range antiferromagnetic order. It is responsible for the splitting out of a narrow band from a Hubbard subband with doping for U = 8t and low T. This segregated band is located near the Fermi level and forms a pseudogap here.The influence of long-range spin and charge fluctuations on spectra of the two-dimensional (2D) fermionic Hubbard model is considered using the strong coupling diagram technique (SCDT). Infinite sequences of diagrams containing ladder inserts, which describe the interaction of electrons with these fluctuations, are summed, and obtained equations are self-consistently solved for the range of Hubbard repulsions 4t [Formula: see text]U [Formula: see text] 8t and temperatures 0.3t [Formula: see text] T [Formula: see text] t with t the intersite hopping constant. It was found that a metal–insulator transition curve goes from larger U and T to smaller values of these parameters. The temperature decrease causes the transition to the long-range antiferromagnetic order. It is responsible for the splitting out of a narrow band from a Hubbard subband with doping for U = 8t and low T. This segregated band is located near the Fermi level and forms a pseudogap here.

arXiv:1708.05818International Journal of Modern Physics BMar 26, 20181 citation

Spin and charge fluctuations of the two-dimensional Hubbard model

Yasushi Shiina

Abstracts of the meeting of the Physical Society of Japan. Sectional meetingSep 12, 19950 citations

Spin fluctuation effects in the normal state of Hubbard systems

Joan Costa-Quintana, F. López‐Aguilar, Antoni Pérez-Navarro +1 more

Physica B Condensed MatterFeb 1, 19976 citations

Precursors of Antiferromagnetic and Hubbard Bands in the 2D Hubbard Model

Bumsoo Kyung

We formulate a theory to the 2D Hubbard model in a framework free of finite size effect and numerical analytical continuation, yet containing the essential features of the 2D Hubbard model, i.e., the correct atomic limit for large frequencies and 2D spin fluctuations. As temperature is decreased for a 2D half-filled band, 2D critical fluctuations give rise to a strong local maximum in the scattering rates at the chemical potential leading to a split peak in the spectral function. As U is increased, four peaks associated with antiferromagnetic and Hubbard bands begin to develop in small and intermediate frequency regimes.We formulate a theory to the 2D Hubbard model in a framework free of finite size effect and numerical analytical continuation, yet containing the essential features of the 2D Hubbard model, i.e., the correct atomic limit for large frequencies and 2D spin fluctuations. As temperature is decreased for a 2D half-filled band, 2D critical fluctuations give rise to a strong local maximum in the scattering rates at the chemical potential leading to a split peak in the spectral function. As U is increased, four peaks associated with antiferromagnetic and Hubbard bands begin to develop in small and intermediate frequency regimes.

arXiv:cond-mat/9802113Feb 11, 19980 citations

To shed light into the pairing mechanism of possible spin triplet superconductors

{(\text{TMTSF})}_{2}X

and

{\text{Sr}}_{2}{\text{RuO}}_{4}

, we study the competition among various spin singlet and triplet pairing channels in the Hubbard model by calculating the pairing interaction vertex using the ground state quantum Monte Carlo technique. We model

{(\text{TMTSF})}_{2}X

by a quarter-filled quasi-one-dimensional (quasi-1D) Hubbard model, and the $\ensuremath{\gamma}$ band of

{\text{Sr}}_{2}{\text{RuO}}_{4}

by a two-dimensional (2D) Hubbard model with a band filling of $\ensuremath{\sim}4∕3$. For the quasi-1D system, we find that triplet

f

-wave pairing not only dominates over the triplet

p

wave in agreement with the spin fluctuation theory, but also looks unexpectedly competitive against

d

waves. For the 2D system, although the results suggest the presence of an attractive interaction in the triplet pairing channels, the

d

-wave pairing interaction is found to be larger than those of the triplet channels.