Penetration depth measurements of singlehyphen;crystal NbN films at millimeterhyphen;wave region

摘要

The zero temperature penetration depth &lgr;(0) of single‐crystal NbN thin films has been measured at 82 GHz using an open resonator. The NbN films used in this study have a (200) single‐crystal structure andTcand &rgr;20(normal state resistivity at 20 K) are 16 K and 62 m&OHgr; cm, respectively. &lgr;(0) was obtained by applying a least‐squares fit to the change of penetration depth using the BCS theory. We obtain &lgr;(0)=194 nm, which shows good agreement with the calculated value fromTc,&rgr;20and &Dgr;(0). ©1996 American Institute of Physics.