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Trapped Soliton Precision Clock

IP.com Disclosure Number: IPCOM000038489D
Original Publication Date: 1987-Jan-01
Included in the Prior Art Database: 2005-Jan-31
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Davidson, A: AUTHOR [+2]

Abstract

This article relates generally to a timing circuit and, more particularly, to such a circuit controlled by a trapped soliton to control an oscillator. Precision clocking can be accomplished through the use of a trapped soliton in a cryostat to phase lock an oscillator and achieve an accuracy of one part in ten raised to the 12th power. A soliton, a quantum of magnetic flux, can be trapped in an annular Josephson junction 1 of metal base electrode 2 and counter electrode 3 under suitable conditions. This occurs when the ring is first cooled through the superconducting transition temperature of the electrodes, and the soliton moves around the ring 1 at a velocity approach ing the speed of light in the tunnel junction barrier. The rotating soliton can be used for phase locking a timing circuit. In Fig.

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Trapped Soliton Precision Clock

This article relates generally to a timing circuit and, more particularly, to such a circuit controlled by a trapped soliton to control an oscillator. Precision clocking can be accomplished through the use of a trapped soliton in a cryostat to phase lock an oscillator and achieve an accuracy of one part in ten raised to the 12th power. A soliton, a quantum of magnetic flux, can be trapped in an annular Josephson junction 1 of metal base electrode 2 and counter electrode 3 under suitable conditions. This occurs when the ring is first cooled through the superconducting transition temperature of the electrodes, and the soliton moves around the ring 1 at a velocity approach ing the speed of light in the tunnel junction barrier. The rotating soliton can be used for phase locking a timing circuit. In Fig. 2, annular junction 1 is supported in liquid helium 4 in a temperature stabilized cryostat 5, and leads 6 provide DC bias current. Capacitive pick-up electrode 7, in close proximity to the junction, receives a cyclic excitation signal that is transmitted outside the cryostat to amplifier 8 at ambient temperature. The amplified signal is fed to phase-sensitive detector 9 and filter 10 to stabilize voltage-controlled oscillator 11, whose output is a highly stable timing signal. Annular junction 1 must be shielded from outside radiation, such as the oscillator output. Portions of this circuit can be modified for placement in the cryostat....