Polarons and dressed molecules near narrow Feshbach resonances
Polarons and dressed molecules near narrow Feshbach resonances
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DOI：
10.1209/0295-5075/98/10012
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发表时间：
2011-12
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影响因子：
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通讯作者：
P. Massignan
中科院分区：
文献类型：
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作者：
P. Massignan
浸没在大费米海中的杂质的性质很自然地用修饰准粒子来描述：吸引和排斥极化子，以及修饰分子。受最近窄Feshbach共振实验的启发，我们在这里分析了准粒子性质如何受到非零共振范围的影响。我们发现两个有趣的分析结果。对于大范围，接近共振的基态能量在反范围内变得微扰。在宽共振的极限下，我们给出了一个新的Tan关系式，它将杂质基态能量E↓与其缀饰云中的原子数ΔN联系起来。作为一个推论，在么正性下，我们发现ΔN=−E↓/<$F，其中<$F是熔池的费米能。
The properties of impurities immersed in a large Fermi sea are naturally described in terms of dressed quasiparticles: attractive and repulsive polarons, and dressed molecules. Motivated by recent experiments on narrow Feshbach resonances, we analyze here how the quasiparticle properties are affected by a non-zero resonance range. We find two interesting analytic results. For large range, the ground-state energy close to resonance is shown to become perturbative in the inverse range. In the limit of broad resonance instead, we provide a new Tan's relation linking the impurity ground-state energy E↓ to the number of atoms in its dressing cloud ΔN. As a corollary, at unitarity one finds ΔN=−E↓/ϵF, with ϵF the Fermi energy of the bath.