Transport properties of the underdoped films in high magnetic fields

¹ National Laboratory for Superconductivity Institute of Physics & Center for Condensed Matter Physics Chinese Academy of Sciences - Beijing 100080, PRC
² Laboratorium voor Vaste-Stoffysica en Magnetisme, Katholieke Universiteit Leuven Celestijnenlaan 200 D, B-3001 Leuven, Belgium

Corresponding authors: hao@istec.or.jp brzhao@aphy.iphy.ac.cn Victor.Moshchalkov@fys.kuleuven.ac.be

Received: 17 January 2001
Accepted: 10 January 2002

Abstract

The effect of magnetic field and disorder on the transport properties of the underdoped films has been investigated in a broad temperature range in magnetic fields up to 50. In ultrathin films with strong disorder, where the mean free path l corresponds to , a convincing power law resistivity vs. temperature (–0.39) is observed in a very broad temperature range –40. However, in superconducting thicker films with much weaker disorder ( in normal state), the high magnetic field, by suppressing superconductivity, recovers the normal-state transport behavior with the -dependence at low temperature in field. The two different transport behaviors indicate that the normal-state transport properties of the underdoped cuprates are very sensitive not only to the hole concentration but also to the degree of the disorder.