论文标题
在超级流体费米气体中激发长寿的希格斯模式，并去除粒子
Exciting the long-lived Higgs mode in superfluid Fermi gases with particle removal
论文作者
论文摘要
直到最近才观察到Higgs模式在强烈相互作用的超流体气体中的实验证据[Behrle等，Nat。物理。 14，781（2018）]。由于与其他集体模式和准粒子激发的耦合，生成稳定的希格斯模式振荡是具有挑战性的。我们研究了如何在BCS-BEC跨界的均质超流体费米气体中激发长寿命的希格斯模式振荡。我们发现，通过以适当的振幅和频率调节散射长度，可以激发希格斯模式。但是，即使对于配对差距能量的调制频率低于两倍，由于超级流体中的非线性导致较高的谐波，准粒子仍然会激发准粒子。更重要的是，我们发现可以通过在适当的动量下去除粒子来产生具有几乎恒定振幅的持续性HigGS模式振荡，并且可以通过去除的颗粒数量来控制振荡振幅。最后，我们提出了两种实验实现粒子去除的方法。
Experimental evidence of the Higgs mode in strongly interacting superfluid Fermi gases had not been observed until recently [Behrle et al., Nat. Phys. 14, 781 (2018)]. Due to the coupling with other collective modes and quasiparticle excitations, generating stable Higgs-mode oscillations is challenging. We study how to excite long-lived Higgs-mode oscillations in a homogeneous superfluid Fermi gas in the BCS-BEC crossover. We find that the Higgs mode can be excited by time-periodically modulating the scattering length at an appropriate amplitude and frequency. However, even for a modulation frequency below twice the pairing-gap energy, quasiparticles are still excited through the generation of higher harmonics due to nonlinearity in the superfluid. More importantly, we find that persistent Higgs-mode oscillations with almost constant amplitude can be produced by removing particles at an appropriate momentum, and the oscillation amplitude can be controlled by the number of removed particles. Finally, we propose two ways to experimentally realize particle removal.
