Ti hot electron bolometers with Johnson noise readout for terahertz radiation detection

25 Jul 2019, 17:45
1h 15m
Piazza Città di Lombardia (Milano)

Piazza Città di Lombardia

Milano

Piazza Città di Lombardia, 1, 20124 Milano MI
Poster Low Temperature Detector Development and Physics Poster session

Speaker

Dr Wei MIAO (Purple Mountain Observatory)

Description

Johnson noise thermometry is a primary measurement technique that can be used to probe the thermal transport and thermodynamic properties of hot electrons in conductors. With this technique, a hot electron bolometer (HEB), consisting of a 20 nm thick titanium (Ti) microbridge and a niobium (Nb) log spiral antenna, was developed for terahertz radiation detection. The Nb antenna with large energy gap is used as a superconducting Andreev reflector to confine the hot electrons in the Ti microbridge. We measured the thermal conductance and electrical noise equivalent power (NEP) of the Ti bolometer at different bath temperatures. We found that the thermal conductance of the Ti bolometer has a temperature dependence of Tn with the index n=2.2. The measured NEP of the Ti bolometer shows similar temperature dependence. At a bath temperature of 3.0 K, the measured NEP is found to be about 20.9 pW/Hz0.5. Using 285/77 K blackbody loads, we also performed the optical NEP measurement at 3.0 K. The measurement shows the Ti bolometer has an optical NEP of ~48.9 pW/Hz0.5.

Less than 5 years of experience since completion of Ph.D N
Student (Ph.D., M.Sc. or B.Sc.) N

Primary author

Dr Wei MIAO (Purple Mountain Observatory)

Co-authors

Mr Hao GAO (Purple Mountain Observatory) Dr Zheng WANG (Purple Mountain Observatory) Dr Wen ZHANG (Purple Mountain Observatory) Dr Yuan REN (Purple Mountain Observatory) Dr Kangmin ZHOU (Purple Mountain Observatory) Dr Jiaqiang ZHONG (Purple Mountain Observatory) Dr Shengcai SHI (Purple Mountain Observatory)

Presentation Materials