Microscopic observation of magnon bound states and their dynamics
Abstract
The existence of bound states of elementary spin waves (magnons) in one-dimensional quantum magnets was predicted almost 80 years ago. Identifying signatures of magnon bound states has so far remained the subject of intense theoretical research and their detection has proved challenging for experiments. Ultracold atoms offer an ideal setting in which to find such bound states by tracking the spin dynamics with single-spin and single-site resolution, following a local excitation. Here we use in situ correlation measurements to observe two-magnon bound states directly in a one-dimensional Heisenberg spin chain comprising ultracold bosonic atoms in an optical lattice. We observe the quantum dynamics of free and bound magnon states through time-resolved measurements of two spin impurities. The increased effective mass of the compound magnon state results in slower spin dynamics as compared to single-magnon excitations. We also determine the decay time of bound magnons, which is probably limited by scattering on thermal fluctuations in the system. Our results provide a new way of studying fundamental properties of quantum magnets and, more generally, properties of interacting impurities in quantum many-body systems.
Additional Information
© 2013 Macmillan Publishers Limited. Received 27 May 2013. Accepted 06 August 2013. Published online 25 September 2013. We thank H. G. Evertz, M. Haque, J.-S. Caux and W. Zwerger for discussions. We thank J. Zeiher for proofreading the manuscript. This work was supported by MPG, DFG, EU (NAMEQUAM, AQUTE, Marie Curie Fellowship to M.C.) and JSPS (Postdoctoral Fellowship for Research Abroad to T.F.). Author Contributions: All authors contributed extensively to the work presented in this paper. The authors declare no competing financial interests.Attached Files
Submitted - 1305.6598v2.pdf
Supplemental Material - nature12541-sf1.jpg
Supplemental Material - nature12541-sf2.jpg
Supplemental Material - nature12541-sf3.jpg
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Additional details
- Eprint ID
- 67416
- Resolver ID
- CaltechAUTHORS:20160527-073235392
- Max-Planck-Gesellschaft
- Deutsche Forschungsgemeinschaft (DFG)
- European Research Council (ERC)
- Marie Curie Fellowship
- Japan Society for the Promotion of Science (JSPS)
- Created
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2016-05-27Created from EPrint's datestamp field
- Updated
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2021-11-11Created from EPrint's last_modified field