Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK.
School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
Nat Commun. 2016 Sep 15;7:12784. doi: 10.1038/ncomms12784.
One-dimensional electronic fluids are peculiar conducting systems, where the fundamental role of interactions leads to exotic, emergent phenomena, such as spin-charge (spinon-holon) separation. The distinct low-energy properties of these 1D metals are successfully described within the theory of linear Luttinger liquids, but the challenging task of describing their high-energy nonlinear properties has long remained elusive. Recently, novel theoretical approaches accounting for nonlinearity have been developed, yet the rich phenomenology that they predict remains barely explored experimentally. Here, we probe the nonlinear spectral characteristics of short GaAs quantum wires by tunnelling spectroscopy, using an advanced device consisting of 6000 wires. We find evidence for the existence of an inverted (spinon) shadow band in the main region of the particle sector, one of the central predictions of the new nonlinear theories. A (holon) band with reduced effective mass is clearly visible in the particle sector at high energies.
一维电子流体是奇特的导电系统，其中相互作用的基本作用导致了奇异的涌现现象，例如自旋电荷（spinon-holon）分离。这些一维金属的独特低能性质在线性 Luttinger 液体理论中得到了成功描述，但描述其高能非线性性质的艰巨任务长期以来一直难以捉摸。最近，已经开发出了新的考虑非线性的理论方法，但它们所预测的丰富现象学在实验上几乎没有得到探索。在这里，我们通过隧道谱法探测了短 GaAs 量子线的非线性光谱特性，使用了由 6000 根线组成的先进器件。我们在粒子区的主要区域发现了存在反转（spinon）影子带的证据，这是新的非线性理论的中心预测之一。在高能区，在粒子区可以清楚地看到具有减小的有效质量的（holon）带。
