Asymmetry with respect to the magnetic field direction in the interaction between the quantum states of two coupled superconducting rings

TL;DR

This study investigates the asymmetric interaction of quantum states in two coupled superconducting rings, revealing magnetic field direction asymmetry and complex frequency interactions through voltage measurements and advanced analysis.

Contribution

It presents the first observation of deviation from magnetic field oddness in the voltage response of coupled superconducting rings.

Findings

Detection of various combination frequencies indicating interaction

Observation of asymmetry in voltage response with respect to magnetic field direction

Analysis confirms complex quantum interactions in asymmetric microstructure

Abstract

The interaction between the quantum states of two aluminum superconducting rings forming an 8-shape circular-asymmetric microstructure was examined under a threading magnetic flux and bias by an alternating current without a dc component. Quantum oscillations of the rectified dc voltage Vdc(B) as a function of magnetic field were measured in the 8-shape microstructure at various bias ac currents and temperatures close to critical. Fourier and wavelet analyses of Vdc(B) functions revealed the presence of various combination frequencies in addition to two ring fundamental frequencies, which suggests the interaction in the structure. Deviation of the Vdc(B) function from oddness with respect to the magnetic field direction was found for the first time.