Tang S-J, Basile L, Miller T, Chiang T-C
Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801-3080, USA.
Phys Rev Lett. 2004 Nov 19;93(21):216804. doi: 10.1103/PhysRevLett.93.216804. Epub 2004 Nov 18.
Quantum well states in thin films are commonly described in terms of a quasiparticle confined in a quantum box, but this single-particle picture can fail dramatically near a substrate band edge, as shown by this angle-resolved photoemission study. Atomically uniform Ag films are prepared on Ge(111) to facilitate accurate line shape and dispersion relation measurements. A quantum well peak is observed to split into two peaks near the Ge valence band edge. The unusual line shapes are shown to be due to many-body interactions and are quantitatively explained by a Green's function calculation.
薄膜中的量子阱态通常用限制在量子盒中的准粒子来描述，但正如这项角分辨光电子能谱研究所表明的，这种单粒子图像在靠近衬底带边缘时可能会显著失效。在Ge(111)上制备原子级均匀的Ag薄膜，以利于精确测量线形和色散关系。观察到一个量子阱峰在靠近Ge价带边缘处分裂成两个峰。结果表明，这种不寻常的线形是由多体相互作用引起的，并且通过格林函数计算进行了定量解释。
