Zobrazeno 1 - 10
of 119
pro vyhledávání: '"Yokoyama, Hisatoshi"'
Publikováno v:
J. Phys. Soc. Jpn. 91, 124705 (2022)
In connection with recent experiments on excitation in which Mott insulators change to conductors, we study the properties of excited states beyond the Mott gap as quasi-stationary states for a two-dimensional Hubbard (t-t'-U) model at half filling.
Externí odkaz:
http://arxiv.org/abs/2210.03276
Publikováno v:
J. Phys. Soc. Jpn. 85, 124707 (2016)
The stability and other properties of a staggered flux (SF) state or a correlated d-density wave state are studied for the Hubbard (t-t'-U) model on extended square lattices, as a low-lying state that competes with the d(x2-y2)-wave superconductivity
Externí odkaz:
http://arxiv.org/abs/1610.04818
Autor:
Sato, Ryo, Yokoyama, Hisatoshi
Publikováno v:
Journal of the Physical Society of Japan 85, 074701 (2016)
Band renormalization effects (BRE) are comprehensively studied for a mixed state of dx2-y2-wave superconducting (d-SC) and antiferromagnetic (AF) orders, in addition to simple d-SC, AF, and normal (paramagnetic) states, by applying a variational Mont
Externí odkaz:
http://arxiv.org/abs/1605.04514
Autor:
Toga, Yuta, Yokoyama, Hisatoshi
Publikováno v:
Phys. Proc. 81, 13 (2016)
Anticipating realization of interacting fermions in an optical lattice with a large gauge field, we consider phase transitions and loop currents in a two-dimensional S=1/2 fermionic-Hubbard model with $\pi$/2-staggered flux at half filling. We use a
Externí odkaz:
http://arxiv.org/abs/1511.04225
Autor:
Tamura, Shun, Yokoyama, Hisatoshi
Publikováno v:
J. Phys. Soc. Jpn. 84, 064707 (2015)
Drude weight ($D$) is a useful measure to distinguish a metal from an insulator. However, $D$ has not been justifiably estimated by the variation theory for long, since Millis and Coppersmith [Phys. Rev. B 43 (1991) 13770] pointed out that a variatio
Externí odkaz:
http://arxiv.org/abs/1502.04799
Publikováno v:
J. Phys. Soc. Jpn. 82, 014707 (2013)
With high-Tc cuprates in mind, properties of correlated dx2-y2-wave superconducting (SC) and antiferromagnetic (AF) states are studied for the Hubbard (t-t'-U) model on square lattices, using a variational Monte Carlo method. We employ simple trial w
Externí odkaz:
http://arxiv.org/abs/1208.1102
Publikováno v:
J. Phys. Soc. Jpn. 81, 063001 (2012)
We study the ground state properties of spin-1 bosons in a two-dimensional optical lattice, by applying a variational Monte Carlo method to the S=1 Bose-Hubbard model on a square lattice at unit filling. A doublon-holon binding factor introduced in t
Externí odkaz:
http://arxiv.org/abs/1204.1175
Autor:
Tamura, Shun, Yokoyama, Hisatoshi
Publikováno v:
J. Phys. Soc. Jpn. 81, 064718 (2012)
We study properties of normal, superconducting (SC) and CDW states for an attractive Hubbard model on the square lattice, using a variational Monte Carlo method. In trial wave functions, we introduce an interspinon binding factor, indispensable to in
Externí odkaz:
http://arxiv.org/abs/1203.1719
Publikováno v:
J. Phys. Soc. Jpn. 80 (2011) 084607
To understand the mechanism of Mott transitions in case of no magnetic influence, superfluid-insulator (Mott) transitions in the S=0 Bose Hubbard model at unit filling are studied on the square and triangular lattices, using a variational Monte Carlo
Externí odkaz:
http://arxiv.org/abs/1104.0516
Autor:
Miyagawa, Tomoaki, Yokoyama, Hisatoshi
The mechanism of Mott transition in the Hubbard model on the square lattice is studied without explicit introduction of magnetic and superconducting correlations, using a variational Monte Carlo method. In the trial wave functions, we consider variou
Externí odkaz:
http://arxiv.org/abs/1104.0109