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Parametric Amplifier or Mixer Based on the Flux Quantization in a Thin Walled SuperConducting Cylinder

IP.com Disclosure Number: IPCOM000045549D
Original Publication Date: 1983-Apr-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

McLachlan, DS: AUTHOR

Abstract

The nonlinear feature upon which the device is b ased is extremely sharp and has a low resistance, if any. Therefore, good amplification and noise characteristics may be obtained.

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Parametric Amplifier or Mixer Based on the Flux Quantization in a Thin Walled SuperConducting Cylinder

The nonlinear feature upon which the device is b ased is extremely sharp and has a low resistance, if any. Therefore, good amplification and noise characteristics may be obtained.

McLachlan (Phys. Rev. Lett. 23, 1434 (1969)) observed that the AC susceptibility of a thin-walled (t<Lambda) hollow superconducting microcylinder exhibits a series of "paramagnetic" spikes as a function of magnetic field. These spikes occur at .5 H, 1.5 H, 2.5 H ---, where H = Phi(o)/cross-sectional area of the cylinder. A sketch of the results obtained is shown in Fig. 1, which shows a trace of the AC signal or magnetic susceptibility Chi as a function of H applied or H outside with spikes 13 in AC susceptibility.

Fig. 2 is a schematic diagram of a system with a lockin amplifier 20. The system includes an AC primary coil 21, a superconducting cylinder 22, an AC secondary coil 23, an input coil 24, and a DC field feedback coil 25 in concentric cylinders of decreasing size. Additional input coils are connected via line 26 to input coil 24. The AC input 30 of amplifier 20 is connected via line 28 to secondary coil 23. The DC output 31 of amplifier 20 is connected via line 29 to coil 25. he AC output 32 of amplifier 20 is connected via line 27 to AC primary coil 21.

The system shown In Fig. Q can lock the system onto one of the spikes 13 by feeding the output of the phase-sensitive detect...