Institut für Theoretische Physik, Johann Wolfgang Goethe-Universität, 60438 Frankfurt/Main, Germany.
Phys Rev Lett. 2011 May 20;106(20):205303. doi: 10.1103/PhysRevLett.106.205303.
We report the first detection of the Higgs-type amplitude mode using Bragg spectroscopy in a strongly interacting condensate of ultracold atoms in an optical lattice. By the comparison of our experimental data with a spatially resolved, time-dependent bosonic Gutzwiller calculation, we obtain good quantitative agreement. This allows for a clear identification of the amplitude mode, showing that it can be detected with full momentum resolution by going beyond the linear response regime. A systematic shift of the sound and amplitude modes' resonance frequencies due to the finite Bragg beam intensity is observed.
我们首次在光学晶格中强相互作用的超冷原子凝聚体中通过布拉格光谱检测到希格斯型幅度模式。通过将我们的实验数据与空间分辨的、时变玻色子 Gutzwiller 计算进行比较，我们得到了很好的定量一致性。这使得幅度模式的明确识别成为可能，表明通过超越线性响应范围，可以以全动量分辨率检测到它。由于有限的布拉格光束强度，观察到声子和幅度模式的共振频率发生了系统的偏移。
