Bolometric Response of High-Tc Superconducting Detectors to Optical Pulses and Continuous Waves

Abstract

This work presents a thermal analysis on predicting the temperature increase and the voltage response of high-Tc superconducting bolometers. Two heat transfer models, that is, the surface heating model and the heat generation model considering the skin depth, are introduced and compared. The surface heating model is found to be valid only for situations where the skin depth is much smaller than the film thickness. To consider the thermal boundary resistance between film and substrate, a radiation-boundary-condition model based on acoustic mismatch model (AMM) and an interfacial-layer model (ILM) are employed. The thermal boundary resistance significantly influences the voltage response. Additionally, several common substrates are examined. SrTiO3 (100) or LaAlO3 (100) is a better substrate for high-Tc superconducting bolometers. One interesting finding was that when compared with experimental data, all the theoretical values from the present study as well as the other previously theoretical treatment overestimate the voltage response near the transition temperature.

Spherical and cylindrical conductive thermal diodes based on VO2

“…Our results agree well with literature hysteresis [9,22], that VO 2 exhibits a dielectric-to-metal transition at a critical temperature (∼ 340 K). Our results also agree with what was proposed by [38][39][40] that thermal resistance influences the heat transfer mechanism. It can also be seen that in the spherical diode, the values of heat flux generated are higher than that of the cylindrical one.…”

Intrinsic thermal stability and quenching recovery of thin-film superconductors with thermal boundary resistance

“…Chen et aI. [9] calculated the sound velocity in two ways, from the elastic bulk modulus, and also from the Debye temperature, and suggested that 1"=0.2 for YBCO/MgO.…”

“…The second model, the interfacial layer model (ILM) assumes an interfacial layer of variable thickness exists inside the superconducting film, and that the diffusivity of it is significantly lower (-10-100 times) than that of bulk YBCO [6]. Chen et al [9] were the first to employ the two models for theoretical analysis of an YBCO/substrate thermal system.…”

Inverse determination of surface temperature in thin-film/substrate systems with interface thermal resistance

“…For example, a restriction in heat flow from the superconducting film can cause a transition from the superconducting state to the normal state during operation of the device, resulting in device failure. Recently, interface thermal resistance has received special interest and attention in many fields such as microelectronics systems [3], superlattices [4,5], and superconductor film/ substrate composites [6][7][8][9]. Many experiments have been conducted to determine the interface thermal resistance between thin films and substrates.…”