Quantized lattice dynamic effects on the spin-Peierls transition
The density-matrix renormalization-group method is used to investigate the spin-Peierls transition for Heisenberg spins coupled to quantized phonons. We use a phonon spectrum that interpolates between a gapped, dispersionless (Einstein) limit to a gapless, dispersive (Debye) limit. A variety of theo...
| Main Authors: | , , |
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| Format: | Journal article |
| Language: | English |
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2010
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| _version_ | 1826281775732621312 |
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| author | Pearson, C Barford, W Bursill, R |
| author_facet | Pearson, C Barford, W Bursill, R |
| author_sort | Pearson, C |
| collection | OXFORD |
| description | The density-matrix renormalization-group method is used to investigate the spin-Peierls transition for Heisenberg spins coupled to quantized phonons. We use a phonon spectrum that interpolates between a gapped, dispersionless (Einstein) limit to a gapless, dispersive (Debye) limit. A variety of theoretical probes are used to determine the quantum phase transition, including energy gap crossing, a finite-size scaling analysis, bond-order autocorrelation functions, and bipartite quantum entanglement. All these probes indicate that in the antiadiabatic phonon limit a quantum phase transition of the Berezinskii-Kosterlitz-Thouless type is observed at a nonzero spin-phonon coupling, gc. An extrapolation from the Einstein limit to the Debye limit is accompanied by an increase in gc for a fixed optical (q=π) phonon gap. We therefore conclude that the dimerized ground state is more unstable with respect to Debye phonons with the introduction of phonon-dispersion renormalizing the effective spin-lattice coupling for the Peierls-active mode. We also show that the staggered spin-spin and phonon displacement order parameters are unreliable means of determining the transition. © 2010 The American Physical Society. |
| first_indexed | 2024-03-07T00:33:53Z |
| format | Journal article |
| id | oxford-uuid:80bbe94d-becd-4e44-912f-71281ad7169f |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T00:33:53Z |
| publishDate | 2010 |
| record_format | dspace |
| spelling | oxford-uuid:80bbe94d-becd-4e44-912f-71281ad7169f2022-03-26T21:25:20ZQuantized lattice dynamic effects on the spin-Peierls transitionJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:80bbe94d-becd-4e44-912f-71281ad7169fEnglishSymplectic Elements at Oxford2010Pearson, CBarford, WBursill, RThe density-matrix renormalization-group method is used to investigate the spin-Peierls transition for Heisenberg spins coupled to quantized phonons. We use a phonon spectrum that interpolates between a gapped, dispersionless (Einstein) limit to a gapless, dispersive (Debye) limit. A variety of theoretical probes are used to determine the quantum phase transition, including energy gap crossing, a finite-size scaling analysis, bond-order autocorrelation functions, and bipartite quantum entanglement. All these probes indicate that in the antiadiabatic phonon limit a quantum phase transition of the Berezinskii-Kosterlitz-Thouless type is observed at a nonzero spin-phonon coupling, gc. An extrapolation from the Einstein limit to the Debye limit is accompanied by an increase in gc for a fixed optical (q=π) phonon gap. We therefore conclude that the dimerized ground state is more unstable with respect to Debye phonons with the introduction of phonon-dispersion renormalizing the effective spin-lattice coupling for the Peierls-active mode. We also show that the staggered spin-spin and phonon displacement order parameters are unreliable means of determining the transition. © 2010 The American Physical Society. |
| spellingShingle | Pearson, C Barford, W Bursill, R Quantized lattice dynamic effects on the spin-Peierls transition |
| title | Quantized lattice dynamic effects on the spin-Peierls transition |
| title_full | Quantized lattice dynamic effects on the spin-Peierls transition |
| title_fullStr | Quantized lattice dynamic effects on the spin-Peierls transition |
| title_full_unstemmed | Quantized lattice dynamic effects on the spin-Peierls transition |
| title_short | Quantized lattice dynamic effects on the spin-Peierls transition |
| title_sort | quantized lattice dynamic effects on the spin peierls transition |
| work_keys_str_mv | AT pearsonc quantizedlatticedynamiceffectsonthespinpeierlstransition AT barfordw quantizedlatticedynamiceffectsonthespinpeierlstransition AT bursillr quantizedlatticedynamiceffectsonthespinpeierlstransition |