Characterization and reduction of unexplained noise in superconducting transition-edge sensors

Abstract

Complex impedance, responsivity and noise of transition-edge sensors: Analytical solutions for two-and threeblock thermal models AIP Advances 2, 042110 (2012); 10.1063/1.4759111 Frequency-domain multiplexed readout of transition-edge sensor arrays with a superconducting quantum interference device Appl. Phys. Lett. 86, 112511 (2005); 10.1063/1.1884746 Prototype system for superconducting quantum interference device multiplexing of large-format transition-edge sensor arrays Rev. Sci. Instrum. 74, 4500 (2003); 10.1063/1.1605259 Time-division superconducting quantum interference device multiplexer for transition-edge sensors Rev. Sci. Instrum. 74, 3807 (2003);

Opportunities for mesoscopics in thermometry and refrigeration: Physics and applications

“…The metal lattice can be considerably refrigerated if the thermal resistance between phonons and the substrate is not negligible compared to that between electrons and phonons. One effective method to meet this requirement, that was suggested at the beginning of cooling experiments ͑Nahum et al., 1994;Fisher et al, 1995͒ as well as for detector applications ͑Nahum and Martinis, 1995; Irwin et al, 1996;Deiker et al, 2004;Pekola, Schoelkopf, and Ullom, 2004;Ullom et al, 2004͒, is to exploit a thermally isolated thin dielectric membrane on which the N region of the cooler is extended. In this way, tunneling through the NIS junction will cool down electrons and the phonons of the metal ͑via electron-phonon coupling͒.…”

Energy resolution of terahertz single-photon-sensitive bolometric detectors

“…We note that the frequency-dependence of the device noise is well described by the Lortentzian functional form expected for statistical thermal fluctuations, and it does not exhibit the excess noise seen in larger-area superconducting transition edge sensors. 15 If the amplifier noise temperature were reduced to T N 1 K, as reported in recent studies, 16,17 the total energy resolution would be dominated by intrinsic device noise rather than by amplifier noise. The amplifier noise and the thermal fluctuation noise contributions to the energy resolution should both scale as the square root of the active device volume.…”

Normal metal-superconductor decoupling as a source of thermal fluctuation noise in transition-edge sensors

“…In contrast, the lower resistivity Mo/Au or Mo/Cu devices usually have a lower excess noise level that is white voltage noise, in other words noise that looks like excess Johnson noise 3,24 . Our model could perhaps explain part of this difference between Ti based and Mo based devices through the higher thermal conductance g T ES,1 of the Mo/Au and Mo/Cu TES films.…”

“…Although the performance of these detectors is already excellent, the most sensitive TES devices have not yet reached the theoretical limits in energy resolution. This is mostly due to excess noise that has been shown to be present in many devices [3][4][5][6][7] . Several candidates for the noise sources have been proposed, such as thermal fluctuations within the TES 5 , fluctuations in the Cooper-pair density 8,9 or phase-slips 10,11 , but a definitive answer is still missing.…”