Subgap structures in the current-voltage characteristic of the intrinsic Josephson effect due to phonons

摘要

A modified RSJ-model for the coupling of intrinsic Josephson oscillations andc-axis phonons in the high-T_c superconductors Tl_2Ba_2Ca_2Cu_3O_{10+\delta}and Bi_2Sr_2CaCu_2O_{8+\delta} is deveoped. This provides a very goodexplanation for recently reported subgap structures in the I-V-characteristicof the c-axis transport. It turns out that the voltages of these structurescoincide with the eigenfrequencies of longitudinal optical phonons, providing anew measurement technique for this quantity. The significantly enhancedmicrowave emission at the subgap structures in both the GHz and THz region isdiscussed.