Effect of an input coil microwave resonance on dynamics and noise properties of a dc superconducting quantum interference device operating close to the hysteretic mode

Autor:	R. Hart, J.M. Lumley, V. Polushkin, D. Glowacka
Rok vydání:	1999
Předmět:	Josephson effect Physics Condensed matter physics Physics::Medical Physics Resonance Noise (electronics) law.invention SQUID Nuclear magnetic resonance Coil noise law Scanning SQUID microscopy Electromagnetic coil Condensed Matter::Superconductivity Magnetic flux quantum Instrumentation
Zdroj:	Review of Scientific Instruments. 70:1713-1718
ISSN:	1089-7623 0034-6748
DOI:	10.1063/1.1149656
Popis:	The dynamics and noise of a dc superconducting quantum interference device (SQUID) with the McCumber parameter βc=2πR2IcC/Φ0 close to the unity (where Ic, R, C are the critical current, the shunt resistance, and the capacitance of the Josephson junctions comprising the SQUID, respectively, and Φ0=2.07×10−15 Wb is the magnetic flux quantum) integrated with a planar spiral input coil have been experimentally studied. The length of the spiral input coil was chosen to match its λ/4 microwave resonance frequency to the plasma resonance frequency of the SQUID. The input coil resonance enhances the overall quality factor Q of the Josephson oscillations in the SQUID and, as a result, increases the dynamic resistance Rd and the gradient of the flux-to-voltage characteristics ∂V/∂Φ without hysteresis. This relaxes the tolerance for the βc parameter, simplifies the technological process, and improves the yield of devices. A dc SQUID with loop inductance L=31.4 pH, βc=0.72, and a six turn input coil has demonstrated ...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::39ee9f29eea4a3a8f4b4a2fa72c8dbdc https://doi.org/10.1063/1.1149656 Zobrazit plný text záznamu