Temperature distribution in a stack of intrinsic Josephson junctions with their CuO-plane electrodes oriented perpendicular to supporting substrate

Abstract

We numerically study Joule heating in a THz emitter made of Bi2Sr2CaCu2O8 + δ (Bi2212) single crystal with its CuO planes oriented perpendicular to supporting substrate. The single crystal is glued to the substrate by a layer of PMMA. The electrical current is applied in the c-axis direction across many intrinsic Josephson junctions (IJJ’s) in Bi2212. The calculations show that the internal temperature increases to an acceptable 10–20 K only above the bath temperature for a Joule power density of ∼ 105 W cm − 3 typical for experiments on THz emission from IJJ’s. This makes the suggested geometry promising for boosting the output power of the emitter.

Thermal and electromagnetic properties ofBi2Sr2CaCu2O8intrinsic Josephson junction stacks studied via one-dimensional coupled sine-Gordon e

“…A crucial point in the physics of the huge IJJ stacks is overheating 3,5,[7][8][9]18,23,26,49,54,56,62,66,67 . For sufficiently low bias currents, the temperature rises only slightly to values above the bath temperature T bath and the voltage across the stack V increases with increasing bias current I.…”

Three-Dimensional Simulations of the Electrothermal and Terahertz Emission Properties ofBi2Sr2CaCu2Rudau1, Wieland2, Langer3 et al. 2016Phys. Rev. Applied300270View full textAdd to dashboardCite

“…For the best stacks, an emission power P e in the range of tens of µW has been achieved 17,19,20,32,33 , and arrays of mesas showed emission with P e up to 0.61 mW 19 . The physics of the huge IJJ stacks is affected by Joule heating 1, 3,5,6,8,13,18,22,26,30,49,52,54,55,63 . For sufficiently low bias currents, the temperature rises only slightly to values above the bath temperature T bath and the voltage V across the stack increases with increasing bias current I.…”

“…This value was recently improved to 2.4 THz for disk-shaped stacks 33 . In terms of modeling, many calculations of electrodynamics have been based on a homogeneous temperature distribution, while calculations of the thermal properties were based on solving the heat diffusion equations in the absence of Josephson currents 49,52,54 . Some attempts have been made to combine both electrodynamics and thermodynamics, either by using arrays of point-like IJJs 59,60,64 or by incorporating temperature-induced effects into an effective model describing the whole stack as a single "giant" junction 55,62,63 …”

3D simulations of the electrothermal and THz emission properties of Bi$_2$Sr$_2$CaCu$_2$O$_8$ intrinsic Josephson junction stacks

“…The physics of the huge IJJ stacks is affected by Joule heating 1, 3,5,6,8,13,18,22,26,30,49,52,54,55,63 . For sufficiently low bias currents, the temperature rises only slightly to values above the bath temperature T bath and the voltage V across the stack increases with increasing bias cur-rent I.…”