Evidence against superconductivity in flux trapping experiments on hydrides under high pressure & On magnetic field screening and expulsion in hydride superconductors

Abstract

It has recently been reported that hydrogen-rich materials under high pressure trap magnetic flux, a tell-tale signature of superconductivity [arXiv:2206.14108v1]. Here we point out that under the protocol used in these experiments the measured results indicate that the materials don't trap magnetic flux. Instead, the measured results are either experimental artifacts or originate in magnetic properties of the sample or its environment unrelated to superconductivity, Together with other experimental evidence analyzed earlier, this clearly indicates that these materials are not superconductors. {\bf In a second part, we discuss magnetic field screening and expulsion.}

arXiv commentThe first part of this submission was posted on arXiv on 14 July 2022 and published in J Supercond Nov Magn 35, 3141 (2022). The second part was originally submitted for posting to arXiv on 14 Nov. 2022 (unsuccessfully) and is under consideration for publication in Nature Communications

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• Quantifying the nonadiabaticity strength constant in recently discovered highly-compressed superconductors
• Broadening of In-Field Superconducting Transitions in Hydrides
• On magnetic field screening and trapping in hydrogen-rich high-temperature superconductors: unpulling the wool over readers' eyes
• On the trapped magnetic moment in type-II superconductors
• Trapped flux in a small crystal of CaKFe${}_4$As${}_4$ at ambient pressure and in a diamond anvil pressure cell
• Is MgB${}_2$ a superconductor?
• Comment on "Trapped flux in a small crystal of CaKFe${}_4$As${}_4$ at ambient pressure and in a diamond anvil pressure cell" by S. L. Bud'ko et al