Roton-type mode softening in a quantum gas with cavity-mediated long-range interactions
| Autor: | Tobias Donner, Renate Landig, Ferdinand Brennecke, Rafael Mottl, Tilman Esslinger, Kristian Baumann |
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| Rok vydání: | 2012 |
| Předmět: |
Condensed Matter::Quantum Gases
Phase transition Quantum Physics Multidisciplinary Condensed matter physics Chemistry Condensed Matter::Other Quantum simulator FOS: Physical sciences Roton Ab initio quantum chemistry methods Quantum Gases (cond-mat.quant-gas) Spectroscopy Quantum Physics (quant-ph) Condensed Matter - Quantum Gases Softening Superfluid helium-4 Excitation |
| Zdroj: | Science (New York, N.Y.). 336(6088) |
| ISSN: | 1095-9203 |
| Popis: | Long-range interactions in quantum gases are predicted to give rise to an excitation spectrum of roton character, similar to that observed in superfluid helium. We investigate the excitation spectrum of a Bose-Einstein condensate with cavity-mediated long-range interactions, which couple all particles to each other. Increasing the strength of the interaction leads to a softening of an excitation mode at a finite momentum, preceding a superfluid to supersolid phase transition. We study the mode softening spectroscopically across the phase transition using a variant of Bragg spectroscopy. The measured spectrum is in very good agreement with ab initio calculations and, at the phase transition, a diverging susceptibility is observed. The work paves the way towards quantum simulation of long-range interacting many-body systems. 10 pages, 5 figures, supplementary materials |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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