Service de Physique de l'État Condensé (CNRS URA 2464), IRAMIS/SPEC, CEA Saclay, 91191 Gif-sur-Yvette, France.
Phys Rev Lett. 2011 Apr 15;106(15):156810. doi: 10.1103/PhysRevLett.106.156810.
We study an electron interferometer formed with a quantum point contact and a scanning probe tip in a two-dimensional electron gas. The images giving the conductance as a function of the tip position exhibit fringes spaced by half the Fermi wavelength. For a contact opened at the edges of a quantized conductance plateau, the fringes are enhanced as the temperature T increases and can persist beyond the thermal length l(T). This unusual effect is explained by assuming a simplified model: The fringes are mainly given by a contribution which vanishes when T→0 and has a decay characterized by a T-independent scale.
我们研究了由二维电子气中的量子点接触和扫描探针尖端形成的电子干涉仪。给出电导随探针位置变化的图像显示出间距为费米波长一半的条纹。对于在量子化电导平台边缘打开的接触，随着温度 T 的增加，条纹会增强，并且可以在热长度 l(T)之外持续存在。这种不寻常的效应可以通过假设一个简化模型来解释：条纹主要由当 T→0 时消失的贡献给出，并且具有由 T 独立的标度表征的衰减。
