Essence of intrinsic tunneling: Distinguishing instrinsic features from artifacts

The out-of-plane current-voltage (I-V) characteristics of Bi2212 are studied in experimental environments of different heat transfer efficiency, allowing practical separation of intrinsic and extrinsic phenomena. The intrinsic (heating-free) response is Ohmic in the normal state of Bi2212, while its resistance R=V/I, is found to be a good practical measure of the mean temperature of the sample in the overheated case. A self-heating model proposed for the latter case provides a qualitative and quantitative description of key findings of intrinsic tunneling spectroscopy including (pseudo)gaps, quasiparticle and normal-state resistances. The model also naturally explains the superconducting gap closure well below T-c of the material as well as its survival at a magnetic field significantly exceeding H-c2. The generic shape of the individual branches of the brushlike part of I-V established under conditions of negligible overheating suggests a phase-slip origin of the intrinsic Josephson effect. The obtained results suggest a convenient practical tool to study normal state resistance R-N(T) and magnetoresistance R-N(B,T) below the T-c(B) of the layered cuprate.