Comparison of two approaches for the treatment of Gutzwiller variational wave functions

Kaczmarczyk, Jan

doi:10.1080/14786435.2014.965235

Cited by 18 publications

(30 citation statements)

References 44 publications

(116 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To account for nonlocal spatial correlations in finite dimensions, higher orders of the expansion (k > 0) are systematically incorporated in Eq. (4) and expectation values of the products of the operators are evaluated diagrammatically [25,26,[42][43][44][45][46][47]. By construction [25], the convergence of the sum with respect to k is reached relatively quickly, and here we found that k = 4 is already satisfying (see the Supplemental Material [48]).…”

mentioning

confidence: 83%

Many-body breakdown of indirect gap in topological Kondo insulators

Wysokiński

Fabrizio

2016

Phys. Rev. B

View full text Add to dashboard Cite

We show that the inclusion of nonlocal correlation effects in a variational wave function for the ground state of a topological Anderson lattice Hamiltonian is capable of describing both topologically trivial insulating phases and nontrivial ones characterized by an indirect gap, as well as its closure at the transition into a metallic phase. The method, though applied to an oversimplified model, thus captures the metallic and insulating states that are indeed observed in a variety of Kondo semiconductors, while accounting for topologically nontrivial band structures. PACS numbers: 71.27.+a, 71.30.+h, 03.65.Vf Introduction. Phenomena at the crossroads of topological insulators and strongly correlated systems have recently gained a lot of attention, mainly stimulated by theoretical proposals that the inclusion of strong correlations in specific models with a nontrivial topological content may give rise to novel and interesting phenomena [1][2][3][4][5]. However, electronic correlations in most of the discovered topological insulators [6,7] seem to be relatively weak, and hence of minor importance. For that reason, the concept of topological Kondo insulators (TKIs) originally put forward in Refs.[8] and [9] is particularly appealing due to its possible realization in already known Kondo insulating compounds [10]. Notably, SmB 6 is convincingly confirmed to be a TKI [11][12][13][14][15][16][17][18][19] with strong evidence of the essential role played by many-body correlations [20,21].Theoretically, the main physical properties of TKI are frequently described in the framework of topological Anderson lattice models in which strong spin-orbit coupling is encoded into a spin-dependent hybridization with odd parity in momentum space [8,9,22]. Many-body correlations in these models have been mostly treated by the slave-boson approach or by the dynamical mean-field theory (DMFT), and predicted to induce quantum phase transitions between topologically distinct bulk insulating phases [22][23][24].The aim of this work is to demonstrate that accounting for nonlocal spatial correlations, beyond those already well captured by the mentioned techniques, plays an important role in modeling TKIs. Specifically, those nonlocal correlations supply the f electron self-energy with a momentum dependence, which is otherwise purely local within DMFT and at the saddle point of the slave-boson theory. Remarkably, such a momentum dependence allows one to describe, above a critical interaction strength, the emergence of a topological Kondo insulator with an indirect gap, and its subsequent closure at the transition into a metallic state, an intriguing result opposite to the conventional Mott phenomenon where increasing interaction instead favours the onset of an insulating state. We disclose this scenario in two dimensions by means of the diagrammatic expansion of the Gutzwiller wave function (GWF) technique [25,26]. CeIrSb [35]). Moreover, assuming that increasing pressure roughly corresponds to reducing the interaction strength, we can ...

show abstract

mentioning

confidence: 83%

Many-body breakdown of indirect gap in topological Kondo insulators

Wysokiński

Fabrizio

2016

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…40, it is equivalent to the method based on the Lagrange multipliers which in turn guarantees the preservation of the statistical consistency during the minimization procedure.…”

Section: Methodsmentioning

confidence: 99%

Effect of interlayer processes on the superconducting state within thet−J−Umodel: Full Gutzwiller wave-function solution and relation to experiment

Zegrodnik

Spałek

2017

Phys. Rev. B

View full text Add to dashboard Cite

The Gutzwiller wave function solution of the t-J-U model is considered for the bilayer high-TC superconductor by using the so-called diagrammatic expansion method. The focus is on the influence of the interlayer effects on the superconducting state. The chosen pairing symmetry is a mixture of d x 2 −y 2 symmetry within the layers and the so-called s ± symmetry for the interlayer contribution. The analyzed interlayer terms reflect the interlayer electron hopping, the interlayer exchange coupling, and the interlayer pair hopping. The obtained results are compared with selected experimental data corresponding to the copper-based compound Bi-2212 with two Cu-O planes in the unit cell. For the sake of comparison, selected results for the case of the bilayer Hubbard model are also provided. This paper complements our recent results obtained for the single-plane high temperature cuprates (cf. Ref. 26).

show abstract

“…Jastrow intersite factors 53 . Here we use an alternative method of evaluating the expectation values for GWF, namely a systematic dia- grammatic expansion for the Gutzwiller wave function (DE-GWF) [54][55][56][57][58] . This method was formulated initially for the Hubbard model in two dimensions in the context of Pomeranchuk instability 54 , and applied subsequently to the description of high-temperature superconductivity for the Hubbard 55,58 and the t-J 56 models.…”

Section: Introductionmentioning

confidence: 99%

Gutzwiller wave-function solution for Anderson lattice model: Emerging universal regimes of heavy quasiparticle states

2015

View full text Add to dashboard Cite

The recently proposed diagrammatic expansion (DE) technique for the full Gutzwiller wave function (GWF) is applied to the Anderson lattice model. This approach allows for a systematic evaluation of the expectation values with full Gutzwiller wave function in the finite dimensional systems. It introduces results extending in an essential manner those obtained by means of standard Gutzwiller approximation (GA) scheme which is variationally exact only in infinite dimensions. Within the DE-GWF approach we discuss principal paramagnetic properties and their relevance to the heavy fermion systems. We demonstrate the formation of an effective, narrow f -band originating from atomic f -electron states and subsequently interpret this behavior as a direct itineracy of f -electrons; it represents a combined effect of both the hybridization and the correlations reduced by the Coulomb repulsive interaction. Such feature is absent on the level of GA which is equivalent to the zeroth order of our expansion. Formation of the hybridization-and electron-concentrationdependent narrow f -band rationalizes common assumption of such dispersion of f levels in the phenomenological modeling of the band structure of CeCoIn5. Moreover, it is shown that the emerging f -electron direct itineracy leads in a natural manner to three physically distinct regimes within a single model, that are frequently discussed for 4f -or 5f -electron compounds as separate model situations. We identify these regimes as: (i) mixed-valence regime, (ii) Kondo-insulator border regime, and (iii) Kondo-lattice limit when the f -electron occupancy is very close to the f -states half-filling, n f → 1. The nonstandard features of emerging correlated quantum liquid state are stressed.

show abstract

Comparison of two approaches for the treatment of Gutzwiller variational wave functions

Cited by 18 publications

References 44 publications

Many-body breakdown of indirect gap in topological Kondo insulators

Many-body breakdown of indirect gap in topological Kondo insulators

Effect of interlayer processes on the superconducting state within thet−J−Umodel: Full Gutzwiller wave-function solution and relation to experiment

Gutzwiller wave-function solution for Anderson lattice model: Emerging universal regimes of heavy quasiparticle states

Contact Info

Product

Resources

About