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Title: Atom cooling by nonadiabatic expansion

Motivated by the recent discovery that a reflecting wall moving with a square-root-in-time trajectory behaves as a universal stopper of classical particles regardless of their initial velocities, we compare linear-in-time and square-root-in-time expansions of a box to achieve efficient atom cooling. For the quantum single-atom wave functions studied the square-root-in-time expansion presents important advantages: asymptotically it leads to zero average energy whereas any linear-in-time (constant box-wall velocity) expansion leaves a nonzero residual energy, except in the limit of an infinitely slow expansion. For finite final times and box lengths we set a number of bounds and cooling principles which again confirm the superior performance of the square-root-in-time expansion, even more clearly for increasing excitation of the initial state. Breakdown of adiabaticity is generally fatal for cooling with the linear expansion but not so with the square-root-in-time expansion.
Authors:
 [1] ;  [2] ;  [1] ;  [3] ;  [4] ;  [5]
  1. Departamento de Quimica-Fisica, UPV-EHU, Apdo 644, 48080 Bilbao (Spain)
  2. (China)
  3. Institute for Mathematical Sciences, Imperial College London, 53 Princes Gate, SW7 2PG London (United Kingdom)
  4. (United Kingdom)
  5. Institut fuer Theoretische Physik, Leibniz Universitaet Hannover, Appelstrasse 2, 30167 Hannover (Germany)
Publication Date:
OSTI Identifier:
21352388
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 80; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevA.80.063421; (c) 2009 The American Physical Society
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ATOMS; COMPARATIVE EVALUATIONS; COOLING; EXCITATION; EXPANSION; RUBIDIUM; WAVE FUNCTIONS ALKALI METALS; ELEMENTS; ENERGY-LEVEL TRANSITIONS; EVALUATION; FUNCTIONS; METALS