Quantum-classical crossover in the spin-1/2 Heisenberg-Kitaev kagome magnet
The spin-1/2 Heisenberg kagome antiferromagnet is one of the paradigmatic playgrounds for frustrated quantum magnetism, with an extensive number of competing resonating valence bond (RVB) states emerging at low energies, including gapped and gapless spin liquids and valence bond crystals. Here we re...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2020-08-01
|
| Series: | Physical Review Research |
| Online Access: | http://doi.org/10.1103/PhysRevResearch.2.033217 |
| _version_ | 1797211372346408960 |
|---|---|
| author | Yang Yang Natalia B. Perkins Fulya Koç Chi-Huei Lin Ioannis Rousochatzakis |
| author_facet | Yang Yang Natalia B. Perkins Fulya Koç Chi-Huei Lin Ioannis Rousochatzakis |
| author_sort | Yang Yang |
| collection | DOAJ |
| description | The spin-1/2 Heisenberg kagome antiferromagnet is one of the paradigmatic playgrounds for frustrated quantum magnetism, with an extensive number of competing resonating valence bond (RVB) states emerging at low energies, including gapped and gapless spin liquids and valence bond crystals. Here we revisit the crossover from this quantum RVB phase to a semiclassical regime brought about by anisotropic Kitaev interactions, and focus on the precise mechanisms underpinning this crossover. To this end, we introduce a simple parametrization of the classical ground states (GSs) in terms of emergent Ising-like variables, and use this parametrization: (i) to construct an effective low-energy description of the order-by-disorder mechanism operating in a large part of the phase diagram and (ii) to contrast, side by side, exact diagonalization data obtained from the full basis with that obtained from the restricted (orthonormalized) basis of classical GSs. The results reveal that fluctuation corrections from states outside the restricted basis are strongly quenched inside the semiclassical regime (due to the large anisotropy spin gaps), and that the RVB phase survives up to a relatively large value of Kitaev anisotropy K. We further find that the pure Kitaev model admits a subextensive number of one-dimensional symmetries, which explains naturally the absence of classical and quantum order by disorder reported previously. |
| first_indexed | 2024-04-24T10:25:26Z |
| format | Article |
| id | doaj.art-f65a3d8f71e74fc2863aa0945325e57a |
| institution | Directory Open Access Journal |
| issn | 2643-1564 |
| language | English |
| last_indexed | 2024-04-24T10:25:26Z |
| publishDate | 2020-08-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review Research |
| spelling | doaj.art-f65a3d8f71e74fc2863aa0945325e57a2024-04-12T16:58:31ZengAmerican Physical SocietyPhysical Review Research2643-15642020-08-012303321710.1103/PhysRevResearch.2.033217Quantum-classical crossover in the spin-1/2 Heisenberg-Kitaev kagome magnetYang YangNatalia B. PerkinsFulya KoçChi-Huei LinIoannis RousochatzakisThe spin-1/2 Heisenberg kagome antiferromagnet is one of the paradigmatic playgrounds for frustrated quantum magnetism, with an extensive number of competing resonating valence bond (RVB) states emerging at low energies, including gapped and gapless spin liquids and valence bond crystals. Here we revisit the crossover from this quantum RVB phase to a semiclassical regime brought about by anisotropic Kitaev interactions, and focus on the precise mechanisms underpinning this crossover. To this end, we introduce a simple parametrization of the classical ground states (GSs) in terms of emergent Ising-like variables, and use this parametrization: (i) to construct an effective low-energy description of the order-by-disorder mechanism operating in a large part of the phase diagram and (ii) to contrast, side by side, exact diagonalization data obtained from the full basis with that obtained from the restricted (orthonormalized) basis of classical GSs. The results reveal that fluctuation corrections from states outside the restricted basis are strongly quenched inside the semiclassical regime (due to the large anisotropy spin gaps), and that the RVB phase survives up to a relatively large value of Kitaev anisotropy K. We further find that the pure Kitaev model admits a subextensive number of one-dimensional symmetries, which explains naturally the absence of classical and quantum order by disorder reported previously.http://doi.org/10.1103/PhysRevResearch.2.033217 |
| spellingShingle | Yang Yang Natalia B. Perkins Fulya Koç Chi-Huei Lin Ioannis Rousochatzakis Quantum-classical crossover in the spin-1/2 Heisenberg-Kitaev kagome magnet Physical Review Research |
| title | Quantum-classical crossover in the spin-1/2 Heisenberg-Kitaev kagome magnet |
| title_full | Quantum-classical crossover in the spin-1/2 Heisenberg-Kitaev kagome magnet |
| title_fullStr | Quantum-classical crossover in the spin-1/2 Heisenberg-Kitaev kagome magnet |
| title_full_unstemmed | Quantum-classical crossover in the spin-1/2 Heisenberg-Kitaev kagome magnet |
| title_short | Quantum-classical crossover in the spin-1/2 Heisenberg-Kitaev kagome magnet |
| title_sort | quantum classical crossover in the spin 1 2 heisenberg kitaev kagome magnet |
| url | http://doi.org/10.1103/PhysRevResearch.2.033217 |
| work_keys_str_mv | AT yangyang quantumclassicalcrossoverinthespin12heisenbergkitaevkagomemagnet AT nataliabperkins quantumclassicalcrossoverinthespin12heisenbergkitaevkagomemagnet AT fulyakoc quantumclassicalcrossoverinthespin12heisenbergkitaevkagomemagnet AT chihueilin quantumclassicalcrossoverinthespin12heisenbergkitaevkagomemagnet AT ioannisrousochatzakis quantumclassicalcrossoverinthespin12heisenbergkitaevkagomemagnet |