Related papers: Clear evidence against superconductivity in hydrid…
High-temperature conventional superconductivity in hydrogen-rich materials under high pressure has been reportedly found in twelve different compounds in recent years. However, the experimental evidence on which these claims are based has…
Recently, phenyl molecules have been reported to exhibit Meissner effect mainly from magnetization measurements. Realizing zero-resistivity state in these materials seems a challenge due to many practical difficulties but is required to…
Lanthanum hydride has attracted significant attention in recent years due to its signatures of superconductivity at around 250 K (1, 2). However, the megabar pressures required for synthesize and maintain its state present extraordinary…
The question of how a metal becoming superconducting expels a magnetic field is addressed. It is argued that the conventional theory of superconductivity has not answered this question despite its obvious importance. We argue that the…
A superconductor is a material that conducts electric current with no resistance. Superconductivity and magnetism are known to be antagonistic phenomena: superconductors expel weak external magnetic field (the Meissner effect) while a…
A new experimental study by Snider et al. [Nature 586, 373-377 (2020)] reported behavior in a high-pressure carbon-sulfur-hydrogen system that has been interpreted by the authors as superconductivity at room temperature. The sudden drop of…
J. E. Hirsch and F. Marsiglio in their publication, Phys. Rev. B 103, 134505 (2021), assert that hydrogen-rich compounds do not exhibit superconductivity. Their argument hinges on the absence of broadening of superconducting transitions in…
The Meissner effect and the Spin Meissner effect are the spontaneous generation of charge and spin current respectively near the surface of a metal making a transition to the superconducting state. The Meissner effect is well known but, I…
In Ref. [1], Minkov et al reported the time dependence of magnetic moment of hydride materials under high pressure in a diamond anvil cell. Here we point out that the straight lines interpolated with the measurement results give the…
The thermodynamic principle of superfluid flow -- that the energy is minimized at constant entropy -- is applied to superconducting currents to derive the Meissner-Ochsenfeld effect in which magnetic fields are expelled from…
Alfven's theorem states that in a perfectly conducting fluid magnetic field lines move with the fluid without dissipation. When a metal becomes superconducting in the presence of a magnetic field, magnetic field lines move from the interior…
Superconductivity occurs in systems that have a lot of negative charge: the highly negatively charged $(CuO2)^{--}$ planes in the cuprates, negatively charged $(FeAs)^-$ planes in the iron arsenides, and negatively charged $B^-$ planes in…
We point out that the Meissner effect, the process by which a superconductor expels magnetic field from its interior, represents an unsolved puzzle within the London-BCS theoretical framework used to describe the physics of conventional…
From the outset of superconductivity research it was assumed that no electrostatic fields could exist inside superconductors, and this assumption was incorporated into conventional London electrodynamics. Yet the London brothers themselves…
The recent report of superconductivity under high pressure at the record transition temperature of Tc=203K in sulfur hydride has been identified as conventional in view of the observation of an isotope effect upon deuteration. Here it is…
The Meissner effect, the expulsion of magnetic field from the interior of a metal entering the superconducting state, is arguably the most fundamental property of superconductors, discovered in 1933. The conventional theory of…
It is demonstrated that resistive transition at 203 K observed in metallic sulfur hydride system at high pressure can be magnetic (rather than superconducting (SC)) in nature. The onset temperature of genuine superconducting transition in…
In their paper arXiv:2405.08189, Supercond. Sci. Technol. 37 (2024) 065010 [1], Bud'ko et al. present experimental results for trapped magnetic flux for a tiny sample of a type II superconductor. The paper aims to provide evidence in…
A possibility of high, room-temperature superconductivity was predicted for metallic hydrogen in the 1960s. However, metallization and superconductivity of hydrogen are yet to be unambiguously demonstrated in the laboratory and may require…
The discovery of a record high superconducting transition temperature (Tc) of 288 K in a pressurized hydride inspires new hope to realize ambient condition superconductivity. Here, we give a perspective on the theoretical and experimental…