کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1855991 1529849 2015 29 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
NN-coherence vs. tt-coherence: An alternative route to the Gross–Pitaevskii equation
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک و نجوم (عمومی)
پیش نمایش صفحه اول مقاله
NN-coherence vs. tt-coherence: An alternative route to the Gross–Pitaevskii equation
چکیده انگلیسی

We show how a candidate mean-field amplitude can be constructed from the exact wave function of an externally forcedNN-Boson system. The construction makes use of subsidiary (N−1)(N−1)-particle states which are propagated in time in addition to the true NN-particle state, but does not involve spontaneous breaking of the U(1)U(1) symmetry associated with particle number conservation. Provided the flow in Fock space possesses a property which we call maximum stiffness, or tt-coherence, the candidate amplitude actually satisfies the time-dependent Gross–Pitaevskii equation, and then serves as macroscopic wave function of the forced NN-particle system. The general procedure is illustrated in detail by numerical calculations performed for the model of a driven bosonic Josephson junction, which allows one to keep track of all contributions which usually are subject to uncontrolled assumptions. These calculations indicate that macroscopic wave functions can persist even under conditions of strong forcing, but are rapidly destroyed upon entering a regime of chaotic dynamics. Our results provide a foundation for future attempts to manipulate, and actively control, macroscopic wave functions by means of purposefully designed force protocols.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Annals of Physics - Volume 362, November 2015, Pages 482–510
نویسندگان
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