Theoretical prediction of fragile Mott insulators on plaquette Hubbard lattices

Wu, Han‐Qing; He, Rong-Qiang; Meng, Zi Yang; Lu, Zhong-Yi

doi:10.1103/physrevb.91.125128

Cited by 7 publications

(6 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…First-principles calculations indicate that such a planar structure is kinetically stable at low temperature [12,13] and that its energy is a local minimum [12], which suggests that the material can potentially be synthesized in laboratories. Actually, this lattice structure has attracted a lot of research interest recently because it not only is hosted by quite a few real materials [14][15][16][17] but also has various intriguing phases on this lattice that have been revealed by theoretical calculations [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Here we notice another remarkable property of this 2D lattice: its band structure can have perfect Fermisurface (FS) nesting in a wide parameter regime at half filling, which easily leads to antiferromagnetic SDW order.…”

Section: Introductionmentioning

confidence: 99%

Single-orbital realization of high-temperature s± superconductivity in the square-octagon lattice

et al. 2019

View full text Add to dashboard Cite

We propose possible high-temperature superconductivity (SC) with singlet s ± -wave pairing symmetry in the single-orbital Hubbard model on the square-octagon lattice with only nearest-neighbor hopping terms. Three different approaches are engaged to treat with the interacting model for different coupling strengths, which yield consistent result for the s ± pairing symmetry. We propose octagraphene, i.e., a monolayer of carbon atoms arranged into this lattice, as a possible material realization of this model. Our variational Monte Carlo study for the material with realistic coupling strength yields a pairing strength comparable with the cuprates, implying a similar superconducting critical temperature between the two families. This study also applies to other materials with similar lattice structure.

show abstract

Section: Introductionmentioning

confidence: 99%

Single-orbital realization of high-temperature s± superconductivity in the square-octagon lattice

et al. 2019

View full text Add to dashboard Cite

show abstract

“…33,44 The models should be also gapped at half-filling. Thus, the checkerboard Hubbard model 50 and the Hubbard model on the 1/5-depleted square lattice 51 in two dimensions are good candidates. We also note that the Hubbard U is tunable for ultracold fermionic atoms in an optical lattice, [52][53][54][55] which provides a good experimental setting to observe the Nagaoka polaron and MBL studied here.…”

Section: Discussionmentioning

confidence: 99%

On the possibility of many-body localization in a doped Mott insulator

Weng

2016

Sci Rep

Self Cite

View full text Add to dashboard Cite

Many-body localization (MBL) is currently a hot issue of interacting systems, in which quantum mechanics overcomes thermalization of statistical mechanics. Like Anderson localization of non-interacting electrons, disorders are usually crucial in engineering the quantum interference in MBL. For translation invariant systems, however, the breakdown of eigenstate thermalization hypothesis due to a pure many-body quantum effect is still unclear. Here we demonstrate a possible MBL phenomenon without disorder, which emerges in a lightly doped Hubbard model with very strong interaction. By means of density matrix renormalization group numerical calculation on a two-leg ladder, we show that whereas a single hole can induce a very heavy Nagaoka polaron, two or more holes will form bound pair/droplets which are all localized excitations with flat bands at low energy densities. Consequently, MBL eigenstates of finite energy density can be constructed as composed of these localized droplets spatially separated. We further identify the underlying mechanism for this MBL as due to a novel ‘Berry phase’ of the doped Mott insulator, and show that by turning off this Berry phase either by increasing the anisotropy of the model or by hand, an eigenstate transition from the MBL to a conventional quasiparticle phase can be realized.

show abstract

“…The standard multi-orbital RPA [74][75][76][77][78][79][80][81][82][83][84][85][86] approach was used to treat the weak-coupling limit of the model. The largest pairing eigenvalue λ is used to estimate T c by the following equation: [79,87] λ…”

Section: Weak-coupling Limitmentioning

confidence: 99%

“…[15] [15] 4.3. Strong-coupling limit In the strong-coupling limit, the Hubbard model becomes an effective t-J model [86] H…”

Section: Intermediate-couplingmentioning

confidence: 99%

Superconductivity in octagraphene

Jun¹,

Yao²

2022

Chinese Phys. B

View full text Add to dashboard Cite

This article reviews the basic theoretical aspects of octagraphene, an one-atom-thick allotrope of carbon, with unusual two-dimensional (2D) Fermi nesting, hoping to contribute to the new family of quantum materials. Octagraphene has an almost strongest sp 2 hybrid bond similar to graphene, and has the similar electronic band structure as iron-based superconductors, which makes it possible to realize high-temperature superconductivity. We have compared various possible mechanisms of superconductivity, including the unconventional s ± superconductivity based on spin fluctuation and conventional superconductivity based on electron-phonon coupling. Theoretical studies have shown that octagraphene has relatively high structural stability. Although many 2D carbon materials with C 4 carbon ring and C 8 carbon ring structures have been reported, it is still challenging to realize the octagraphene with pure square-octagon structure experimentally. This material holds hope to realize new 2D high-temperature superconductivity.

show abstract

Theoretical prediction of fragile Mott insulators on plaquette Hubbard lattices

Cited by 7 publications

References 43 publications

Single-orbital realization of high-temperature s± superconductivity in the square-octagon lattice

Single-orbital realization of high-temperature s± superconductivity in the square-octagon lattice

On the possibility of many-body localization in a doped Mott insulator

Superconductivity in octagraphene

Contact Info

Product

Resources

About