We present a superconducting bolometer fabricated by a rolled-up technology that allows one to combine the two-dimensionality (2D) of the superconducting layer with a helical spiral curvature. The bolometer is formed as a free-standing Nb nanohelix acting as an ultrathin transition-edge sensor (TES) and having a negligible thermal contact to the substrate. We demonstrate the functionality of the thin-film TES by examining its microwave-detection performance in comparison with a commercial cryogenic bolometer from QMC Instruments. The nanohelix has been revealed to feature a noise equivalent power (NEP) of about 2 × 10–10 W Hz–1/2 at a microwave radiation power of 9 W m–2, which is 4 orders of magnitude smaller than the NEP of the QMC sensor at a similar radiation power. Furthermore, the forecast for the nanohelix is a 1 to 2 orders of magnitude shorter response time as compared to sensors based on commonly used 1 μm thick Si3N4 membranes. The reason is the extremely low heat capacity of the 50 nm thick supporting material and the few contact points between the TES and the substrate. Our findings indicate that microwave radiation detection can be substantially improved by extending 2D superconducting structures into the 3D space.

Multilayer systems consisting of periodic hybrid interfaces show promising applications in thermoelectric design in terms of unique phonon blocking and electron conducting features. Universal techniques combining crystalline semiconductors with various categories of metals, oxides, molecules, and polymers have been rarely reported. In this paper, we first briefly review a novel rolled‐up and compressing technique based on a strain engineered In0.2Ga0.8As/GaAs semiconducting nanomembrane. Then, the controllable rolling and compressing of a nanomembrane, focused ion beam cutting and the following device fabrication steps are demonstrated for the system of a hybrid In0.2Ga0.8As/GaAs/Cr/Au superlattice. Apart from a considerable reduction of thermal conductivity in a similar system reported by part of us very recently, here our efforts are focused on characterizing the cross‐plane electrical conductance of the hybrid superlattice. High electrical conductance of four separated devices show very tight electrical bonding across the hybrid interfaces.