Ultrafast Enhancement of Ferromagnetic Spin Exchange Induced by Ligand-to-Metal Charge Transfer
Abstract
We theoretically predict and experimentally demonstrate a nonthermal pathway to optically enhance superexchange interaction energies in a material based on exciting ligand-to-metal charge-transfer transitions, which introduces lower-order virtual hopping contributions that are absent in the ground state. We demonstrate this effect in the layered ferromagnetic insulator CrSiTe₃ by exciting Te-to-Cr charge-transfer transitions using ultrashort laser pulses and detecting coherent phonon oscillations that are impulsively generated by superexchange enhancement via magneto-elastic coupling. This mechanism kicks in below the temperature scale where short-range in-plane spin correlations begin to develop and disappears when the excitation energy is tuned away from the charge-transfer resonance, consistent with our predictions.
Additional Information
© 2020 American Physical Society. Received 10 December 2019; revised 17 August 2020; accepted 2 October 2020; published 4 November 2020. This work was supported by ARO MURI Grant No. W911NF-16-1-0361. D. H. and G. R. also acknowledge support from the David and Lucile Packard Foundation. D. H. acknowledges support for instrumentation from the Institute for Quantum Information and Matter, an NSF Physics Frontiers Center (PHY-1733907). A. R. acknowledges support from the Caltech Prize Fellowship, the Zuckerman Foundation, and the Israel Science Foundation (Grant No. 1017/20). The MRL Shared Experimental Facilities are supported by the MRSEC Program of the NSF under Grant No. DMR 1720256, a member of the NSF-funded Materials Research Facilities Network. S. D. W. acknowledges support from the Nanostructures Cleanroom Facility at the California NanoSystems Institute (CNSI). G. R. also acknowledges partial support through DOE Award No. DE-SC0019166.Attached Files
Published - PhysRevLett.125.197203.pdf
Submitted - 1910.06376.pdf
Supplemental Material - ARR2_Ron_10-1-2020_SI.pdf
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Additional details
- Eprint ID
- 100322
- Resolver ID
- CaltechAUTHORS:20191217-085020547
- W911NF-16-1-0361
- Army Research Office (ARO)
- David and Lucile Packard Foundation
- Institute for Quantum Information and Matter (IQIM)
- PHY-1733907
- NSF
- Caltech
- Zuckerman Foundation
- 1017/20
- Israel Science Foundation
- DMR-1720256
- NSF
- California NanoSystems Institute
- DE-SC0019166
- Department of Energy (DOE)
- Created
-
2019-12-17Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Institute for Quantum Information and Matter