Investigation of possibility of creation of a superconductor quantum register

TL;DR

This study investigates the potential for creating a superconducting quantum register by examining quantum states in mesoscopic superconducting rings through various measurements, revealing contradictions that challenge classical realism.

Contribution

It provides experimental evidence of quantum oscillations in superconducting rings and discusses implications for quantum computing and the principle of realism.

Findings

Quantum oscillations of resistance and rectified voltage indicate two permitted states.

Oscillations of critical current contradict resistance measurements.

Results suggest possible violation of realism at mesoscopic scale.

Abstract

Multiple and single measurements of quantum states of mesoscopic superconducting loops are carried out in order to investigate a possibility of macroscopic quantum superposition and of creation of a superconductor quantum register. Asymmetric superconducting rings are used in order to be convinced that single measurement gives result corresponding to one of permitted states and multiple one gives an average value on these states. We have measured magnetic dependencies of resistance, rectified voltage and critical current on these rings. The observed quantum oscillations of the resistance and the rectified voltage, corresponding to multiple measurement of quantum states, give evidence of two permitted states at the magnetic flux inside the ring divisible by half of the flux quantum. But the observed quantum oscillations of the critical current, corresponding to single measurement, not only does not confirm these two quantum states, but are in a direct contradiction with the observed oscillations of the resistance. It is assumed that the observed contradiction between the results of measurements made on the same ring can testify to violation of the principle of realism on the mesoscopic level that is a necessary condition for an opportunity of creation of a quantum computer.