Zobrazeno 1 - 10
of 304
pro vyhledávání: '"SANTOS, A. R. DOS."'
Autor:
Kennedy, Welberth, Sousa-Júnior, Sebastião dos Anjos, Costa, Natanael C., Santos, Raimundo R. dos
The lack of both nesting and a van Hove singularity at half filling, together with the presence of Dirac cones makes the honeycomb lattice a special laboratory to explore strongly correlated phenomena. For instance, at zero temperature the repulsive
Externí odkaz:
http://arxiv.org/abs/2411.07429
We theoretically investigate the quantum percolation problem on Lieb lattices in two and three dimensions. We study the statistics of the energy levels through random matrix theory, and determine the level spacing distributions, which, with the aid o
Externí odkaz:
http://arxiv.org/abs/2409.04610
Publikováno v:
Phys. Rev. A 110, 053315 (2024)
The attractive Hubbard model has become a model readily realizable with ultracold atoms on optical lattices. However, the superconducting (superfluid) critical temperatures, $T_c$'s, are still somewhat smaller than the lowest temperatures achieved in
Externí odkaz:
http://arxiv.org/abs/2408.17405
Autor:
Macedo, Thales F., Faúndez, Julián, Santos, Raimundo R. dos, Costa, Natanael C., Pinheiro, Felipe A.
We theoretically investigate the effects of criticality and multifractal states in a one-dimensional Aubry-Andre-Harper model coupled to electromagnetic cavities. We focus on two specific cases where the phonon frequencies are $\omega_{0}=1$ and $\om
Externí odkaz:
http://arxiv.org/abs/2408.06496
Autor:
Albujer, Alma L., Santos, Fábio R. dos
Publikováno v:
Annals of Global Analysis and Geometry 62 (2022), 181-200
Some classification results for closed surfaces in Berger spheres are presented. On the one hand, a Willmore functional for isometrically immersed surfaces into an homogeneous space $\mathbb{E}^{3}(\kappa,\tau)$ with isometry group of dimension $4$ i
Externí odkaz:
http://arxiv.org/abs/2402.04654
Publikováno v:
Proceedings of the Edinburgh Mathematical Society 66 (2) (2023), 346-365
The total mean curvature functional for submanifolds into the Riemannian product space $\mathbb{S}^n\times\mathbb{R}$ is considered and its first variational formula is presented. Later on, two second order differential operators are defined and a ni
Externí odkaz:
http://arxiv.org/abs/2402.04394
We study four spins on a ring coupled through competing Heisenberg interactions between nearest neighbors, $J$, and next-nearest neighbors, $J_2\equiv\alpha J>0$. The spectrum is obtained in a simple way by using the rules for addition of 4 angular m
Externí odkaz:
http://arxiv.org/abs/2308.16204
Autor:
Lima, Lucas O., Medeiros-Silva, Andressa R., Santos, Raimundo R. dos, Paiva, Thereza, Costa, Natanael C.
The interest in the physical properties of kagome lattices has risen considerably. In addition to the synthesis of new materials, the possibility of realizing ultracold atoms on an optical kagome lattice (KL) raises interesting issues. For instance,
Externí odkaz:
http://arxiv.org/abs/2304.12476
The extended Hubbard model (EHM) describes fermions on a lattice coupled through on-site, $U$, and first-neighbor, $V$, interactions. In the context of high-$T_c$ cuprates, antiferromagnetic fluctuations may lead to an attractive channel, hence to su
Externí odkaz:
http://arxiv.org/abs/2304.08683
We investigate how magnetic impurities may affect a system exhibiting charge-density wave (CDW) in its ground state. We consider a disordered Hubbard-Holstein model with a homogeneous electron-phonon interaction, but with a (randomly chosen) fraction
Externí odkaz:
http://arxiv.org/abs/2209.04498