The Meissner effect puzzle and the quantum force in superconductor

Abstract

The puzzle of the acceleration of the mobile charge carriers and the ions in the superconductor in direction opposite to the electromagnetic force revealed formerly in the Meissner effect is considered in the case of the transition of a narrow ring from normal to superconducting state. It is elucidated that the azimuthal quantum force was deduced eleven years ago from the experimental evidence of this acceleration but it can not solve this puzzle. This quantum force explains other paradoxical phenomena connected with reiterated switching of the ring between normal and superconducting states.

On the dynamics of the Meissner effect

“…It has been argued that the explanation (or lack thereof) of the Meissner effect is in essence the same as that of flux quantization in superconducting rings [54,55]. We argue that this is not quite so, even though the phenomena are certainly closely related.…”

Development of a Superconducting Differential Double Contour Interferometer

“…The DDCI may outperform traditional Superconducting Quantum Interference Devices when the change of the quantum number occurs in a narrow magnetic field region near the half of the flux quantum due to thermal fluctuations, quantum fluctuations, or the switching a loop segment in the normal state for a while by short pulse of an external current. Higher sensitivity of DDCI compared to the conventional SQUID is provided by strong discreteness of the energy spectrum of the continuous superconducting loop [6]. According to the conventional theory [7] the total energy of the persistent current…”

“…Higher sensitivity of DDCI compared to the conventional SQUID is provided by strong discreteness of the energy spectrum of the continuous superconducting loop [6]. According to the conventional theory [7] the total energy of the persistent current…”

“…A bias current I flows from the upper loop to the lower loop through two Josephson junctions Ja and J b (labeled with white circles). The maximum value of the superconducting current through these Josephson junctions should depend on parity of the sum nu + n d of the quantum numbers of the upper loop nu and the lower loop n d according to (6). Therefore the voltage measured on DDCI average in the time…”

“…the maximum value of the superconducting current (6), depends only on parity of the quantum number sum, and it does not explicitly depend on the magnetic flux, which makes the system to be an ideal detector of the quantum states. The critical current has only two values at I a = I b = I cj according to (6): I c,DD = 2I c,j when the sum n u + n d of the quantum numbers of the upper loop n u and the bottom loop n d is even and I c = 0 when it is odd. Therefore, for example at Φ = 0.5Φ 0 + δΦ, the maximum value of the superconducting current (6) and the voltage measured on the DDCI at a bias current I may change by jump when the quantum number of the bottom loop should be equal permanently zero n d = 0 whereas the quantum number the upper loop may change from n u = 0 to n u = 1 (or from n u = 1 to n u = 0) after successive switching of the loop segment in the normal state by the short pulse of the external current I sw , Fig.1.…”