TY - JOUR
T1 - Low-temperature properties in the bilayer Kitaev model
AU - Tomishige, Hiroyuki
AU - Nasu, Joji
AU - Koga, Akihisa
N1 - Funding Information:
Parts of the numerical calculations were performed in the supercomputing systems in ISSP, the University of Tokyo. This work was supported by Grants-in-Aid for Scientific Research from JSPS, KAKENHI, Grants No. JP18K04678, No. JP17K05536 (A.K.), No. JP16K17747, No. JP16H02206, and No. JP18H04223 (J.N.).
Publisher Copyright:
© 2019 American Physical Society.
PY - 2019/5/23
Y1 - 2019/5/23
N2 - 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.
AB - 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.
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U2 - 10.1103/PhysRevB.99.174424
DO - 10.1103/PhysRevB.99.174424
M3 - Article
AN - SCOPUS:85066404350
SN - 2469-9950
VL - 99
JO - Physical Review B
JF - Physical Review B
IS - 17
M1 - 174424
ER -