Alexander-Webber J A, Huang J, Beilsten-Edmands J, Čermák P, Drašar Č, Nicholas R J, Coldea A I
Department of Engineering, University of Cambridge, 9 J.J. Thomson Avenue, Cambridge CB3 0FA, United Kingdom.
J Phys Condens Matter. 2018 Apr 18;30(15):155302. doi: 10.1088/1361-648X/aab193. Epub 2018 Feb 22.
We report magnetotransport studies in thin (<100 nm) exfoliated films of Cu BiSe and we detect an unusual electronic transition at low temperatures. Bulk crystals show weak superconductivity with [Formula: see text] K and a possible electronic phase transition around 200 K. Following exfoliation, superconductivity is supressed and a strongly temperature dependent multi-band conductivity is observed for T < 30 K. This transition between competing conducting channels may be enhanced due to the presence of electronic ordering, and could be affected by the presence of an effective internal stress due to Cu intercalation. By fitting to the weak antilocalisation conductivity correction at low magnetic fields we confirm that the low temperature regime maintains a quantum phase coherence length [Formula: see text] nm indicating the presence of topologically protected surface states.
我们报道了对薄（<100nm）的剥离CuBiSe薄膜的磁输运研究，并且我们在低温下检测到了一种不寻常的电子跃迁。块状晶体显示出[公式：见原文]K的弱超导性以及在200K左右可能的电子相变。剥离后，超导性被抑制，并且在T < 30K时观察到强烈依赖于温度的多带导电性。由于电子有序化的存在，这种竞争导电通道之间的跃迁可能会增强，并且可能会受到由于Cu插层而产生的有效内应力的影响。通过拟合低磁场下的弱反局域化电导率修正，我们证实低温区域保持着量子相位相干长度[公式：见原文]nm，这表明存在拓扑保护的表面态。
