Crossover of high-energy spin fluctuations from collective triplons to localized magnetic excitations in Sr14−xCaxCu24O41 ladders
Abstract We studied the magnetic excitations in the quasi-one-dimensional (q-1D) ladder subsystem of Sr14−xCaxCu24O41 (SCCO) using Cu L 3-edge resonant inelastic X-ray scattering (RIXS). By comparing momentum-resolved RIXS spectra with high (x = 12.2) and without (x = 0) Ca content, we track the evo...
| Main Authors: | , , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2022-09-01
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| Series: | npj Quantum Materials |
| Online Access: | https://doi.org/10.1038/s41535-022-00502-1 |
| _version_ | 1811267438600257536 |
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| author | Y. Tseng J. Thomas W. Zhang E. Paris P. Puphal R. Bag G. Deng T. C. Asmara V. N. Strocov S. Singh E. Pomjakushina U. Kumar A. Nocera H. M. Rønnow S. Johnston T. Schmitt |
| author_facet | Y. Tseng J. Thomas W. Zhang E. Paris P. Puphal R. Bag G. Deng T. C. Asmara V. N. Strocov S. Singh E. Pomjakushina U. Kumar A. Nocera H. M. Rønnow S. Johnston T. Schmitt |
| author_sort | Y. Tseng |
| collection | DOAJ |
| description | Abstract We studied the magnetic excitations in the quasi-one-dimensional (q-1D) ladder subsystem of Sr14−xCaxCu24O41 (SCCO) using Cu L 3-edge resonant inelastic X-ray scattering (RIXS). By comparing momentum-resolved RIXS spectra with high (x = 12.2) and without (x = 0) Ca content, we track the evolution of the magnetic excitations from collective two-triplon (2 T) excitations (x = 0) to weakly-dispersive gapped modes at an energy of 280 meV (x = 12.2). Density matrix renormalization group (DMRG) calculations of the RIXS response in the doped ladders suggest that the flat magnetic dispersion and damped excitation profile observed at x = 12.2 originates from enhanced hole localization. This interpretation is supported by polarization-dependent RIXS measurements, where we disentangle the spin-conserving ΔS = 0 scattering from the predominant ΔS = 1 spin-flip signal in the RIXS spectra. The results show that the low-energy weight in the ΔS = 0 channel is depleted when Sr is replaced by Ca, consistent with a reduced carrier mobility. Our results demonstrate that off-ladder impurities can affect both the low-energy magnetic excitations and superconducting correlations in the CuO4 plaquettes. Finally, our study characterizes the magnetic and charge fluctuations in the phase from which superconductivity emerges in SCCO at elevated pressures. |
| first_indexed | 2024-04-12T21:02:37Z |
| format | Article |
| id | doaj.art-79a51a69383b4e9ebfbf18fb3ff016f9 |
| institution | Directory Open Access Journal |
| issn | 2397-4648 |
| language | English |
| last_indexed | 2024-04-12T21:02:37Z |
| publishDate | 2022-09-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | npj Quantum Materials |
| spelling | doaj.art-79a51a69383b4e9ebfbf18fb3ff016f92022-12-22T03:16:48ZengNature Portfolionpj Quantum Materials2397-46482022-09-01711910.1038/s41535-022-00502-1Crossover of high-energy spin fluctuations from collective triplons to localized magnetic excitations in Sr14−xCaxCu24O41 laddersY. Tseng0J. Thomas1W. Zhang2E. Paris3P. Puphal4R. Bag5G. Deng6T. C. Asmara7V. N. Strocov8S. Singh9E. Pomjakushina10U. Kumar11A. Nocera12H. M. Rønnow13S. Johnston14T. Schmitt15Photon Science Division, Paul Scherrer InstitutDepartment of Physics and Astronomy, The University of TennesseePhoton Science Division, Paul Scherrer InstitutPhoton Science Division, Paul Scherrer InstitutLaboratory for Multiscale Materials Experiments, Paul Scherrer InstitutIndian Institute of Science Education and ResearchAustralian Centre for Neutron Scattering, Australian Nuclear Science and Technology OrganisationPhoton Science Division, Paul Scherrer InstitutPhoton Science Division, Paul Scherrer InstitutIndian Institute of Science Education and ResearchLaboratory for Multiscale Materials Experiments, Paul Scherrer InstitutDepartment of Physics and Astronomy, The University of TennesseeDepartment of Physics and Astronomy and Stewart Blusson Quantum Matter Institute, University of British ColumbiaLaboratory for Quantum Magnetism, Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL)Department of Physics and Astronomy, The University of TennesseePhoton Science Division, Paul Scherrer InstitutAbstract We studied the magnetic excitations in the quasi-one-dimensional (q-1D) ladder subsystem of Sr14−xCaxCu24O41 (SCCO) using Cu L 3-edge resonant inelastic X-ray scattering (RIXS). By comparing momentum-resolved RIXS spectra with high (x = 12.2) and without (x = 0) Ca content, we track the evolution of the magnetic excitations from collective two-triplon (2 T) excitations (x = 0) to weakly-dispersive gapped modes at an energy of 280 meV (x = 12.2). Density matrix renormalization group (DMRG) calculations of the RIXS response in the doped ladders suggest that the flat magnetic dispersion and damped excitation profile observed at x = 12.2 originates from enhanced hole localization. This interpretation is supported by polarization-dependent RIXS measurements, where we disentangle the spin-conserving ΔS = 0 scattering from the predominant ΔS = 1 spin-flip signal in the RIXS spectra. The results show that the low-energy weight in the ΔS = 0 channel is depleted when Sr is replaced by Ca, consistent with a reduced carrier mobility. Our results demonstrate that off-ladder impurities can affect both the low-energy magnetic excitations and superconducting correlations in the CuO4 plaquettes. Finally, our study characterizes the magnetic and charge fluctuations in the phase from which superconductivity emerges in SCCO at elevated pressures.https://doi.org/10.1038/s41535-022-00502-1 |
| spellingShingle | Y. Tseng J. Thomas W. Zhang E. Paris P. Puphal R. Bag G. Deng T. C. Asmara V. N. Strocov S. Singh E. Pomjakushina U. Kumar A. Nocera H. M. Rønnow S. Johnston T. Schmitt Crossover of high-energy spin fluctuations from collective triplons to localized magnetic excitations in Sr14−xCaxCu24O41 ladders npj Quantum Materials |
| title | Crossover of high-energy spin fluctuations from collective triplons to localized magnetic excitations in Sr14−xCaxCu24O41 ladders |
| title_full | Crossover of high-energy spin fluctuations from collective triplons to localized magnetic excitations in Sr14−xCaxCu24O41 ladders |
| title_fullStr | Crossover of high-energy spin fluctuations from collective triplons to localized magnetic excitations in Sr14−xCaxCu24O41 ladders |
| title_full_unstemmed | Crossover of high-energy spin fluctuations from collective triplons to localized magnetic excitations in Sr14−xCaxCu24O41 ladders |
| title_short | Crossover of high-energy spin fluctuations from collective triplons to localized magnetic excitations in Sr14−xCaxCu24O41 ladders |
| title_sort | crossover of high energy spin fluctuations from collective triplons to localized magnetic excitations in sr14 xcaxcu24o41 ladders |
| url | https://doi.org/10.1038/s41535-022-00502-1 |
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