تقرير
Goldstone mode and pair-breaking excitations in atomic Fermi superfluids
| العنوان: | Goldstone mode and pair-breaking excitations in atomic Fermi superfluids |
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| المؤلفون: | Hoinka, Sascha, Dyke, Paul, Lingham, Marcus G., Kinnunen, Jami J., Bruun, Georg M., Vale, Chris J. |
| سنة النشر: | 2017 |
| المجموعة: | Condensed Matter Physics (Other) |
| مصطلحات موضوعية: | Condensed Matter - Quantum Gases, Physics - Atomic Physics |
| الوصف: | Spontaneous symmetry breaking is a central paradigm of elementary particle physics, magnetism, superfluidity and superconductivity. According to Goldstone's theorem, phase transitions that break continuous symmetries lead to the existence of gapless excitations in the long-wavelength limit. These Goldstone modes generally dominate the low-energy excitations, showing that symmetry breaking has a profound impact on the physical properties of matter. Here, we present the first comprehensive study of the elementary excitations in a homogeneous strongly interacting Fermi gas through the crossover from a Bardeen-Cooper-Schrieffer (BCS) superfluid to a Bose-Einstein condensate (BEC) of molecules using two-photon Bragg spectroscopy. The spectra exhibit a discrete Goldstone mode, associated with the broken symmetry superfluid phase, as well as pair breaking single-particle excitations. Our techniques yield a direct determination of the superfluid pairing gap and speed of sound in close agreement with a strong-coupling theory. Comment: Original version, full text published online in Nature Physics |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1038/nphys4187 |
| URL الوصول: | http://arxiv.org/abs/1707.00406 |
| رقم الأكسشن: | edsarx.1707.00406 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1038/nphys4187 |
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