Photon-noise-limited cold-electron bolometer based on strong electron self-cooling for high-performance cosmology missions

Abstract

Bolometers for balloon and space missions have seen extensive development because of their capacity to test primordial conditions of the Universe. The major improvements consist in lowering the operating temperature to reach higher sensitivities. Here we show that an array of 192 cold-electron bolometers (CEB) demonstrates photon-noise-limited operation at the cryostat temperature of 310 mK due to effective self-cooling of the absorber. The direct electron cooling of nanoabsorber placed between normal metal-insulator-superconductor junctions has considerably higher efficiency than indirect cooling through massive suspended platform, that requires overcoming a weak electron-phonon conductance. The electron temperature reached 120 mK without a power load, and 225 mK with a 60 pW power load with self-noise of a single bolometer below 3 Á 10 À18 W Hz À1=2 at a 0.01 pW power load. This bolometer works at electron temperature less than phonon temperature, thus being a good candidate for future space missions without the use of dilution refrigerators.

Reaching the ultimate energy resolution of a quantum detector

“…Here, ϵ and μ denote the single particle energy and chemical potential of the system, respectively. We illustrate the calorimeter [11][12][13][14][15] principle of our experiment and set-up in Fig. 1 16 .…”

THz Properties of Long YBaCuO Bicrystal Josephson Junction Studied with a Cold-Electron Bolometer

“…Bolometer response is defined as a voltage difference at a fixed bias current through the CEBs array with and without the JJ radiation. Based on the response characteristic (the inset of Figure 2) the bias current for the bolometer has been chosen aside from the maximum response since there is a minimal value of noise-equivalent-power [3]. Changing the current through the Josephson junction (for zero current through the coil, creating the magnetic field), the signal from the bolometer and the voltage on the YBCO oscillator (which is connected with the oscillation frequency via the Josephson relation) were measured, see Figure 3.…”

“…The saturation power for one CEB is about 0.5 pW. Taking into account the expected power load, the 2-dimensional array of CEBs [48] has been realized as a meander-type structure [3,12]. The receiving system represents a single pixel for the Olimpo balloon experiment, optimized for power loads up to 100 pW.…”

“…The unit cell of dipoles is a modification of the dense rectangular grid, distributed in a more sparse way over the unit cell [48]. The serial and parallel DC connections of CEBs are optimized for impedance matching and minimal overall system noise [3]. The pairs of λ/2 dipoles sensitive to both orthogonal linear polarizations are connected to each other by dc lines with 1 µm width.…”

“…The development of multichroic focal planes for measurements of the CMB is important for increasing the sensitivity of an experiment as well as for removing the contamination due to galactic foregrounds, which is becoming the limiting factor in CMB measurements [2]. The cold-electron bolometer (CEB) is an attractive candidate for these measurements because the decoupling of the phonon and electron subsystems in the tiny absorber gives it such advantages as high sensitivity and high saturation power [3,4] as well as the immunity to cosmic rays [5]. CEBs can be used for on-chip LC-filtering due to a series resonance of the capacitance of SIN junctions and the kinetic inductance of the NbN strip [6][7][8] or the reactance of slot antennas connected by coplanar lines [9,10].…”