论文标题
玻色纤维混合物中的声音传播：从弱相互作用到强相互作用
Sound propagation in a Bose-Fermi mixture: from weak to strong interactions
论文作者
论文摘要
粒子状激发或准粒子，从相互作用的费尔米金和骨气量子场中浮出水面，这是许多有趣的高能和凝结物质系统中许多有趣的量子现象。在强相互作用方向上，这些激发的性质的计算通常是棘手的。量子退化的玻色纤维混合物提供了有前途的前景，以阐明这种准粒子的物理。在这项工作中，我们调查了浸入退化的费米气体中的原子 - 玻色子凝结物中的声子传播，并带有种间散射长度$ a_ \ a_ \ text {bf} $，由feshbach共振调节。我们通过中等吸引人的互动观察到声音模式软化。为了更大的吸引力，令人惊讶的是，稳定的声音传播重新出现并在整个共鸣中持续存在。与谐振相互作用的声子的稳定性为研究强烈相互作用方案中的新型Bose-Fermi液体和费米式配对提供了机会。
Particle-like excitations, or quasi-particles, emerging from interacting fermionic and bosonic quantum fields underlie many intriguing quantum phenomena in high energy and condensed matter systems. Computation of the properties of these excitations is frequently intractable in the strong interaction regime. Quantum degenerate Bose-Fermi mixtures offer promising prospects to elucidate the physics of such quasi-particles. In this work, we investigate phonon propagation in an atomic Bose-Einstein condensate immersed in a degenerate Fermi gas with interspecies scattering length $a_\text{BF}$ tuned by a Feshbach resonance. We observe sound mode softening with moderate attractive interactions. For even greater attraction, surprisingly, stable sound propagation re-emerges and persists across the resonance. The stability of phonons with resonant interactions opens up opportunities to investigate novel Bose-Fermi liquids and fermionic pairing in the strong interaction regime.
