Search for quantum transducers between electromagnetic and gravitational radiation: A measurement of an upper limit on the transducer conversion efficiency of yttrium barium copper oxide

TL;DR

This study investigates the potential of high-temperature superconductor YBCO as a quantum transducer between electromagnetic and gravitational waves, setting an upper limit on conversion efficiency through a novel experimental approach.

Contribution

First experimental attempt to measure EM-GR transduction using YBCO, providing an upper limit on conversion efficiency at liquid nitrogen temperature.

Findings

Upper limit on transducer efficiency: 1.6×10⁻⁵

YBCO shows no detectable EM-GR conversion at tested conditions

Pioneering experiment for quantum transducers between EM and gravitational radiation

Abstract

A minimal coupling rule for the coupling of the electron spin to curved spacetime in general relativity suggests the possibility of a coupling between electromagnetic and gravitational radiation mediated by means of a quantum fluid. Thus quantum transducers between these two kinds of radiation fields might exist. We report here on the first attempt at a Hertz-type experiment, in which a high-$\rm{T_c}$ superconductor (YBCO) was the sample material used as a possible quantum transducer to convert EM into GR microwaves, and a second piece of YBCO in a separate apparatus was used to back-convert GR into EM microwaves. An upper limit on the conversion efficiency of YBCO was measured to be $1.6\times10^{-5}$ at liquid nitrogen temperature.