On the use of ferroelectric material in the detection of dark matter axions

TL;DR

This paper proposes a novel ferroelectric-based electronic tuning method using potassium tantalate for microwave haloscopes, significantly expanding tuning range and reducing mechanical failure risks in dark matter axion detection.

Contribution

It introduces a new ferroelectric tuning element using KTaO3 films as interresonator couplings, enhancing tuning range and system robustness in axion haloscopes.

Findings

Achieved a tuning range of 2.23%, a major improvement over previous <0.1%.

Demonstrated through theoretical and simulated results the effectiveness of ferroelectric tuning.

Proposed a design that reduces mechanical failures in haloscope tuning systems.

Abstract

Tuning is an essential requirement for the search of dark matter axions employing haloscopes since its mass is not known yet to the scientific community. At the present day, most haloscope tuning systems are based on mechanical devices which can lead to failures due to the complexity of the environment in which they are used. However, the electronic tuning making use of ferroelectric materials can provide a path that is less vulnerable to mechanical failures and thus complements and expands current tuning systems. In this work, we present and design a novel concept for using the ferroelectric Potassium Tantalate ($KTaO_3$ or KTO) material as a tuning element in haloscopes based on coupled microwave cavities. In this line, the structures used in the Relic Axion Detector Exploratory Setup (RADES) group are based on several cavities that are connected by metallic irises, which act as interresonator coupling elements. In this article, we also show how to use these $KTaO_3$ films as interresonator couplings between cavities, instead of inductive or capacitive metallic windows used in the past. These two concepts represent a crucial upgrade over the current systems employed in the dark matter axions community, achieving a tuning range of $2.23 \, \%$ which represents a major improvement as compared to previous works ($<0.1 \, \%$) for the same class of tuning systems. The theoretical and simulated results shown in this work demonstrate the interest of the novel concepts proposed for the incorporation of this kind of ferroelectric media in multicavity resonant haloscopes in the search for dark matter axions.