Ground-State Properties for Bilayer Kitaev Model: Dimer Expansion Study

Koga, Akihisa; Tomishige, Hiroyuki; Nasu, Joji

doi:10.1007/s10948-018-4891-5

Cited by 7 publications

(5 citation statements)

References 29 publications

(33 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We thank Donna N. Sheng for the correspondence and discussion about theirs and ours results. model [22][23][24][25]. These ED and TPQ studies show the characteristic two-peak structure of the specific heat for strong J, the excitation energy, and the overall phase diagram as a function of the inter-layer coupling J.…”

Section: Discussionmentioning

confidence: 99%

Characterizing spin-one Kitaev quantum spin liquids

Khait,

Stavropoulos,

Kee

et al. 2020

Preprint

View full text Add to dashboard Cite

Material realizations of the bond-dependent Kitaev interactions with S=1/2 local moments have vitalized the research in quantum spin liquids. Recently, it has been proposed that higher-spin analogues of the Kitaev interactions may also occur in a number of materials with strong spin-orbit coupling. In contrast to the celebrated S=1/2 Kitaev model on the honeycomb lattice, the higherspin Kitaev models are not exactly solvable. Hence, the existence of quantum spin liquids in these systems remains an outstanding question. In this work, we use the density matrix renormalization group (DMRG) methods to numerically investigate the S=1 Kitaev model with both ferromagnetic (FM) and antiferromagnetic (AFM) interactions. Using results on a cylindrical geometry with various circumferences, we conclude that the ground state of the S=1 Kitaev model is a quantum spin liquid with a Z2 gauge structure. We also put a bound on the excitation gap, which turns out to be quite small. The magnetic field responses for the FM and AFM models are similar to those of the S=1/2 counterparts. In particular, in the AFM S=1 model, a gapless quantum liquid state emerges in an intermediate window of magnetic field strength, before the system enters a trivial polarized state.

show abstract

Section: Discussionmentioning

confidence: 99%

Characterizing spin-one Kitaev quantum spin liquids

Khait,

Stavropoulos,

Kee

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…For frustrated interdimer exchange, less research has been performed. In this context, very recently, bilayers of the Kitaev quantum magnet on the honeycomb lattice, coupled by interlayer Heisenberg exchange, have attracted significant attention [12][13][14][15]. A prime reason for this is, that in the limit of weak interlayer coupling, and instead of a local magnetic order parameter of Ginzburg-Landau type, the single layers of this magnet display a quantum spin liquid (QSL) state.…”

Section: Introductionmentioning

confidence: 99%

“…The genuine KHBM [12][13][14][15] displays a remarkably rich set of quantum phases, which depend decisively on the three different ways to stack the bilayer, the intralayer anisotropy of the Kitaev exchange, as well as the ratio of the dimer-to Kitaev-exchange [13]. In particular, and apart from the limiting cases of the weakly interacting quantum dimer phase (QDM) and the Kitaev QSL, an emergent Ising macro-spin phase as well as phase with spontaneous interlayer coherence and flux generation has been uncovered within the phase diagram [13].…”

Section: Introductionmentioning

confidence: 99%

Two-triplon excitations of the Kitaev-Heisenberg-Bilayer

Wagner,

Brenig

2021

Preprint

View full text Add to dashboard Cite

We study the spectrum of a bilayer of Kitaev magnets on the honeycomb lattice, coupled by Heisenberg exchange in the quantum-dimer phase at strong interlayer coupling. Using the perturbative Continuous Unitary Transformation (pCUT) we perform series expansion starting from the fully dimerized limit, to evaluate the elementary excitations, reaching up to and focusing on the two-triplon sector. In stark contrast to conventional bilayer quantum magnets, and because of the broken SU (2)-invariance, encoded in the intralayer directional compass-exchange, the bilayer Kitaev magnet is shown to exhibit a rich structure of two-triplon scattering-state continua, as well as several collective two-triplon (anti)bound states. Direct physical pictures for the occurrence of the latter are provided and the (anti)bound states are studied versus the stacking type, the spin components, and the exchange parameters. In addition to the two-triplon spectra, we investigate a corresponding experimental probe by evaluating the magnetic Raman-scattering intensity. We find a very strong sensitivity of this intensity on the two-triplon interactions and the scattering geometry, however a signal from the (anti)bound states appears only in very close proximity to the continuum.

show abstract

“…Therefore, this gapless QSL state should be stable, in contrast to the QSL state in one dimension. So far, the stability of the QSL in the S = 1/2 Kitaev model has been examined in the presence of perturbations such as magnetic field [11][12][13], Heisenberg interactions [14][15][16][17][18], inverse of the spinorbit coupling [19] and interlayer couplings [20][21][22].…”

Section: Introductionmentioning

confidence: 99%

Low-temperature properties in the bilayer Kitaev model

2019

Self Cite

View full text Add to dashboard Cite

The ground state of the bilayer Kitaev model with the Heisenberg-type interlayer exchange interaction is investigated by means of the exact diagonalization. Calculating the ground-state energy, local quantity defined on each plaquette, and dynamical spin structure factor, we obtain results suggesting the existence of a quantum phase transition between the Kitaev quantum spin liquid (QSL) and dimer singlet states when the interlayer coupling is antiferromagnetic. On the other hand, increasing the ferromagnetic interlayer coupling, there exists no singularity in the physical quantities, suggesting that the S = 1/2 Kitaev QSL state realized in each layer adiabatically connects to another QSL state realized in the S = 1 Kitaev model. Thermodynamic properties are also studied by means of the thermal pure quantum state method.

show abstract

Ground-State Properties for Bilayer Kitaev Model: Dimer Expansion Study

Cited by 7 publications

References 29 publications

Characterizing spin-one Kitaev quantum spin liquids

Characterizing spin-one Kitaev quantum spin liquids

Two-triplon excitations of the Kitaev-Heisenberg-Bilayer

Low-temperature properties in the bilayer Kitaev model

Contact Info

Product

Resources

About