Measuring the dynamic structure factor of a quantum gas undergoing a structural phase transition
| Autor: | Renate Landig, Tilman Esslinger, Rafael Mottl, Ferdinand Brennecke, Tobias Donner |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Physics
Quantum Physics Multidisciplinary Photon Dynamic structure factor FOS: Physical sciences General Physics and Astronomy General Chemistry Inelastic scattering Bioinformatics Article General Biochemistry Genetics and Molecular Biology Inelastic neutron scattering Quantum Gases (cond-mat.quant-gas) Ultracold atom Dissipative system Quasiparticle Atomic physics Quantum Physics (quant-ph) Condensed Matter - Quantum Gases Quantum |
| Zdroj: | Nature Communications Nature Communications, 6 |
| ISSN: | 2041-1723 |
| DOI: | 10.3929/ethz-b-000101960 |
| Popis: | The dynamic structure factor is a central quantity describing the physics of quantum many-body systems, capturing structure and collective excitations of a material. In condensed matter, it can be measured via inelastic neutron scattering, which is an energy-resolving probe for the density fluctuations. In ultracold atoms, a similar approach could so far not be applied because of the diluteness of the system. Here we report on a direct, real-time and nondestructive measurement of the dynamic structure factor of a quantum gas exhibiting cavity-mediated long-range interactions. The technique relies on inelastic scattering of photons, stimulated by the enhanced vacuum field inside a high finesse optical cavity. We extract the density fluctuations, their energy and lifetime while the system undergoes a structural phase transition. We observe an occupation of the relevant quasi-particle mode on the level of a few excitations, and provide a theoretical description of this dissipative quantum many-body system. Nature Communications, 6 ISSN:2041-1723 |
| Databáze: | OpenAIRE |
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