LPEM (UPMC-CNRS), Ecole Supérieure de Physique et de Chimie Industrielles, Paris 75005, France.
Nat Commun. 2010 Jul 27;1:47. doi: 10.1038/ncomms1039.
Elemental bismuth provides a rare opportunity to explore the fate of a three-dimensional gas of highly mobile electrons confined to their lowest Landau level. Coulomb interaction, neglected in the band picture, is expected to become significant in this extreme quantum limit, with poorly understood consequences. Here, we present a study of the angular-dependent Nernst effect in bismuth, which establishes the existence of ultraquantum field scales on top of its complex single-particle spectrum. Each time a Landau level crosses the Fermi level, the Nernst response sharply peaks. All such peaks are resolved by the experiment, and their complex angular dependence is in very good agreement with the theory. Beyond the quantum limit, we resolve additional Nernst peaks signaling a cascade of additional Landau sublevels caused by electron interaction.
元素铋提供了一个难得的机会，可以探索被限制在最低朗道能级的高度迁移电子的三维气体的命运。在能带图中被忽略的库仑相互作用，预计在这个极端量子极限中变得非常重要，其后果还不太清楚。在这里，我们研究了铋的各向异性聂耳效应，该效应证实了在其复杂的单粒子谱之上存在超高量子场尺度。每当一个朗道能级穿过费米能级，聂耳响应就会急剧地达到峰值。实验中可以分辨出所有这些峰值，它们的复杂角依赖性与理论非常吻合。超出量子极限，我们还可以分辨出额外的聂耳峰值，这些峰值表明由于电子相互作用引起的额外朗道子能级的级联。
