QUANTUM-RESONANCE RATCHETS: THEORY AND EXPERIMENT
| Autor: | Gil Summy, Itzhack Dana, Vladislav B. Roitberg, Vijayashankar Ramareddy, Ishan Talukdar |
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| Rok vydání: | 2010 |
| Předmět: |
Condensed Matter::Quantum Gases
Physics Condensed Matter::Other Applied Mathematics Ratchet Acceleration (differential geometry) Ratchet effect Symmetry (physics) law.invention Momentum law Modeling and Simulation Quantum mechanics Atom optics Engineering (miscellaneous) Quantum Bose–Einstein condensate |
| Zdroj: | International Journal of Bifurcation and Chaos. 20:255-261 |
| ISSN: | 1793-6551 0218-1274 |
| DOI: | 10.1142/s0218127410025697 |
| Popis: | A theory of quantum ratchets for a particle periodically kicked by a general periodic potential under quantum-resonance conditions is developed for arbitrary values of the conserved quasimomentum β. A special case of this theory is experimentally realized using a Bose–Einstein condensate (BEC) exposed to a pulsed standing light wave. While this case corresponds to completely symmetric potential and initial wave-packet, a purely quantum ratchet effect still arises from the generic noncoincidence of the symmetry centers of these two entities. The experimental results agree well with the theory after taking properly into account the finite quasimomentum width of the BEC. This width causes a suppression of the ratchet acceleration occurring for "resonant" β, so that the mean momentum saturates to a finite ratchet velocity, strongly pronounced relative to that for nonresonant β. |
| Databáze: | OpenAIRE |
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