Quiet and noisy metastable voltage states in high-Tc superconductors

Abstract

The interaction between the telegraph noise and background voltage fluctuations in the current induced dissipative state of high-T c BiSrCaCuO thin films has been investigated. Experimental time records of the voltage drop across current biased thin film strips show markedly different background noise traces in the up and down telegraph states. Detailed analysis demonstrates that fluctuations around the telegraph voltage levels are due to a unique background noise process. The apparent quiet and noisy voltage states are due only to differences in the effective frequency bandwidth at which background noise is seen at distinct telegraph levels. Changes of the background noise variance ratio with changing bias current follow changes of the statistical average lifetimes of the random telegraph process.

Vortex-induced voltage instabilities in a superconducting BSCCO thin film

“…We assume the standard deviations cup e oDN of the Gaussian background distributions as estimators of the average noise spectral density in the "Up" and "Down" states, respectively. We evaluate the effective measurement bandwidth Bw by the following approximation [8]:…”

Noise evidence for intermittent channeled vortex motion in laser-processed YBaCuO thin films

“…In the case of an extremely non-Gaussian, two-level random telegraph noise (RTN), however, a relatively simple analysis of time-domain records provides significant information about the physical system and involved fluctuators. 6,9 Although the RTN signals frequently appear in the vortex noise of superconductors, the exact mechanism responsible for RTN generation remains to be an open and controversial issue. [5][6][7] One of the proposed mechanisms for the RTN vortex noise is the intermittency of the channeled flow of vortices.…”

“…However, a non-Gaussian vortex noise has been frequently encountered in experiments performed on various, both high-and low-temperature superconductors, in samples ranging from bulk to thin films, with single-crystalline to granular morphologies. [1][2][3][4][5][6][7][8][9][10] Proper characterization of the non-Gaussian noise requires measurements of higher-order moments beyond the usual two-point correlations. In the case of an extremely non-Gaussian, two-level random telegraph noise (RTN), however, a relatively simple analysis of time-domain records provides significant information about the physical system and involved fluctuators.…”

Non-Gaussian noise in quantum wells infrared photodetectors

“…Nevertheless, in many cases, just simple measurement of time traces of non-Gaussian events enables a powerful insight into the involved physics. The best example is the time domain analysis of extremely non-Gaussian random telegraph noise processes [1].…”

“…Nevertheless, in many cases, just simple measurement of time traces of non-Gaussian events enables a powerful insight into the involved physics. The best example is the time domain analysis of extremely non-Gaussian random telegraph noise processes [1].Noise in quantum well infrared photodetectors (QWIPs) was studied extensively in the last years [2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Generationrecombination (GR) noise, closely related to the usual GR noise in classical photodetectors, [16] has been accepted as a dominant noise mechanism in QWIPs.…”