# Multilayer Bolometric Structures for Efficient Wideband Communication Signal Reception
## 1 Introduction  
The demand for communication systems is growing rapidly, prompting engineers and researchers to explore more and more frequency bands. At the same time, it is imperative to address the issue of electromagnetic spectrum pollution [1]. The solution to these two conflicting challenges lies in using low-level radio signal radiation and receivers with quantum sensitivity levels. Devices operating at the single-photon level play a key role in several applications, including boson sampling [2], quantum simulators [3], and linear optical quantum computing [4]. Detectors with quantum sensitivity are currently standard for photons, but only in the optical frequency (wavelength) range [5, 6]. Superconducting bolometric detectors are commonly used for infrared light (e.g., at the important vital wavelength of 1550 nm). In this case, the energy spectrum of the system is such that even a single quantum of radiation puts a thin and narrow superconducting strip into a resistive state (changes the state of the electronic collective). This produces a voltage pulse at the detector output [7, 8, 9]. In contrast to visible and infrared wavelengths, developing devices in the microwave frequency range pose more significant challenges, mainly due to the photon energy that is lower by four orders of magnitude. Detectors based on artificial quantum systems have recentlybeen demonstrated [10; 11; 12; 13]. However, they suffer from several fundamental drawbacks in performing their function: narrow bandwidth, the need to fine-tune parameters during operation, and scalability. This makes them less suitable for practical applications. An alternative approach is to use narrow-bandwidth superconductors to detect microwaves via a pair-breaking mechanism using microwave surface plasmon (SP) sensors. These include kinetic inductance detectors (KIDs) [14; 15], superconducting nanowire single-photon detectors [16; 17], and transition edge sensors [18; 19]. Existing SP-based devices operate in the mid-infrared (IR) region [20; 21]. A practical approach to overcome these challenges is the careful selection of the detector material [22; 23], which can include high-temperature superconductors (HTSC) [24; 25; 26]. The implementation of increasingly complex heterostructures has enabled the development of ultra-sensitive detectors for longer wavelengths and lower photon energies [27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38]. Quantum sensitivity has also been achieved for radiofrequency signals [39; 40]. In our previous article [41], we considered utilizing well-known resonance effects [42; 43; 44; 45; 46; 47] to increase the efficiency of any bolometric detector. By choosing the material and thickness of the dielectric substrate that acts as a resonator so that a half-integer number of standing wavelengths can fit within this size, we can significantly increase the probability of detecting individual photons. It is worth noting that the proposed versions of the high-sensitivity bolometric detectors are resonant. This limits the effective adequate receiving bandwidth. However, the solution is to create broad spectral zones by adding several conductive and dielectric layers (i.e., by constructing anti-reflection nanomaterials). Broad spectral zones of electromagnetic energy absorption make it possible to detect broadband signals. Of course, this solution has a drawback: each layer absorbs and reflects signal energy, reducing the overall energy efficiency of the device. The main objective of the present study is to demonstrate the possibility of broadband electromagnetic signal detection with high efficiency based on the multilayer bolometric structure of conducting and non-conducting layers. Such a receiver should meet the requirements of modern communication applications [48]. This paper unveils the outcomes of comprehensive theoretical and experimental inquiries into the wideband absorption of gigahertz waves within a structure comprising alternating silicon semiconductor and dielectric layers.