Evolution of the Higgs mode in a fermion superfluid with tunable interactions
Evolution of the Higgs mode in a fermion superfluid with tunable interactions
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DOI：
10.1103/physreva.93.033641
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发表时间：
2015-02
影响因子：
2.9
通讯作者：
Boyang Liu;H. Zhai;Shizhong Zhang
中科院分区：
文献类型：
--
作者：
Boyang Liu;H. Zhai;Shizhong Zhang
在这项工作中，我们给出了中性$S波费米子超流体中希格斯模演化的相干图像。当费米子间吸引相互作用的强度从BCS增加到玻色-爱因斯坦凝聚态(BEC)时，我们发现费米子超流体中的Higgs模被推到更高的能量，同时逐渐失去它的光谱重量，这是因为系统调谐远离洛伦兹不变性。此外，在考虑了阻尼的情况下，在整个BEC-BCS交叉过程中，由于耦合到相位模，Higgs模的谱权显著展宽。
In this work we present a coherent picture for the evolution of Higgs mode in neutral $s$-wave fermion superfluids. As the strength of attractive interaction between fermions increases from the BCS to the Bose-Einstein condensate (BEC) regime we find that the Higgs mode in the fermionic superfluids is pushed to higher energy while at the same time, gradually loses its spectral weight, which is because the system is tuned away from Lorentz invariance. Furthermore, when damping is taken into account, the spectral weight of the Higgs mode is significantly broadened due to coupling to phase mode in the whole BEC-BCS crossover.