Spectrum of density, spin and pairing fluctuations of an attractive two-dimensional Fermi gas

التفاصيل البيبلوغرافية
العنوان: Spectrum of density, spin and pairing fluctuations of an attractive two-dimensional Fermi gas
المؤلفون: Apostoli, Christian, Kelly, Patrick, Lopez, Annette, Dauer, Kaelyn, Bertaina, Gianluca, Galli, Davide Emilio, Vitali, Ettore
سنة النشر: 2024
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Quantum Gases
الوصف: We leverage random phase approximation and unbiased auxiliary-field quantum Monte Carlo methods to compute dynamical correlations for a dilute homogeneous two-dimensional attractive Fermi gas. Our main purpose is to quantitatively study the collective excitations of the system to generate robust benchmark results and to shed light into fermionic superfluidity in the strongly correlated regime. In particular we are motivated by a recent paper suggesting that the Higgs mode can be detected in the spectrum of spin fluctuations. Despite the fact that we are somewhat limited by finite-size effects, our study pinpoints indeed a clear peak in the spin channel at low momentum, but a detailed analysis suggests that such a peak, though certainly interesting, does not correspond to the Higgs mode. We propose a different explanation for the shape of the spin structure factor. On the other hand, our results clearly show that the Higgs mode can be detected in the density channel at very small wave vectors, although very good resolution is necessary.
Comment: 10 pages, 5 figures
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2403.13636
رقم الأكسشن: edsarx.2403.13636
قاعدة البيانات: arXiv