V. I. Kuznetsov — Page 2

arXiv2003

Induction of dc voltage, proportional to the persistent current, by external ac current on system of inhomogeneous superconducting loops

A dc voltage induced by an external ac current is observed in system of asymmetric mesoscopic superconducting loops. The value and sign of this dc voltage, like the one of the persistent current, depend in a periodical way on a magnetic field with period corresponded to the flux quantum within the loop. The amplitude of the oscillations does not depend on the frequency of the external ac current (in the investigated region 100 Hz - 1 MHz) and depends on its amplitude. The latter dependence is not monotonous. The observed phenomenon of rectification is interpreted as a consequence of a dynamic resistive state induced by superposition of the external current and the persistent current. It is shown that the dc voltage can be added in system of loops connected in series: the dc voltage oscillations with amplitude up to 0.00001 V were observed in single loop, up to 0.00004 V in a system of 3 loops and up to 0.0003 V in a system of 20 loops.

cond-mat.supr-con↗

arXiv2001

Observation of dc voltage on segments of an inhomogeneous superconducting loop

In order to verify a possibility of a dc voltage predicted on segments of an inhomogeneous superconducting loop the Little-Parks oscillations are investigated on symmetrical and asymmetric Al loops. The amplitude of the voltage oscillations $ΔV$ measured on segments of symmetrical loop increases with the measuring current $I_{m}$ and $ΔV = 0$ at $I_{m}= 0$ in accordance with the classical Little-Parks experiment. Whereas the $ΔV$ measured on segments of asymmetric loop has a maximum value at $I_{m}= 0$. The observation of the dc voltage at $I_{m}= 0$ means that one of the loop segments is a dc power source and others is a load. The dc power can be induced by both thermal fluctuation and a external electric noise.

physics.gen-ph↗