Modeling the linewidth dependence of coherent terahertz emission from intrinsic Josephson junction stacks in the hot-spot regime

作者：Gross B^*; Yuan J; An D Y; Li M Y; Kinev N; Zhou X J; Ji M; Huang Y; Hatano T; Mints R G; Koshelets V P; Wu P H; Wang H B; Koelle D; Kleiner R

来源：Physical Review B, 2013, 88(1): 014524.

DOI：10.1103/PhysRevB.88.014524

Recently, it has been found that, when operated at large input power, the linewidth Delta f of terahertz radiation emitted from intrinsic Josephson junction stacks can be as narrow as some megahertz. In this high-bias regime, a hot spot coexists with regions which are still superconducting. Surprisingly, Delta f was found to decrease with increasing bath temperature. We present a simple model describing the dynamics of the stack in the presence of a hot spot by two parallel arrays of pointlike Josephson junctions and an additional shunt resistor in parallel. Heat diffusion is taken into account by thermally coupling all elements to a bath at temperature T-b. We present current-voltage characteristics of the coupled system and calculations of the linewidth of the radiation as a function of T-b. In the presence of a spatial gradient of the junction parameters%26apos; critical current and resistance, Delta f deceases with increasing T-b, similar to the experimental observation.

• 出版日期2013-7-25
• 单位南京大学