Browse Prior Art Database

Applications of Superconductivity to Information Storage

IP.com Disclosure Number: IPCOM000119691D
Original Publication Date: 1991-Feb-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 2 page(s) / 65K

Publishing Venue

IBM

Related People

Thompson, DA: AUTHOR [+2]

Abstract

High Tc superconductive materials can provide advantages in information storage. Such materials exhibit zero electrical resistance, which can be used to limit Johnson noise in a magnetic recording head and preamplifier, and also to reduce power loss in the motor of a system. However, the major advantage is the shielding which a high Tc superconductor can provide.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Applications of Superconductivity to Information Storage

      High Tc superconductive materials can provide advantages
in information storage.  Such materials exhibit zero electrical
resistance, which can be used to limit Johnson noise in a magnetic
recording head and preamplifier, and also to reduce power loss in the
motor of a system.  However, the major advantage is the shielding
which a high Tc superconductor can provide.

      First, let us consider what sort of advantage might accrue from
the property of zero electrical resistance in a magnetic recording
file.  The principal effect would be to lower the Johnson noise in
the head and preamplifier. Combined with some cooling of the
amplifying element, it should be possible to greatly reduce that
component of the total noise.  However, Johnson noise is only one of
four major noise sources.  The others (media noise, off-track noise,
and electromagnetic interference) would all have to be reduced by a
comparable amount to obtain a substantial signal-to-noise advantage.

      In the internal gap of an inductive head, a superconductive
diamagnetic shield greatly improves efficiency, and greatly decreases
stray inductance. Additional shielding around the coil of a film head
can reduce the technological limit on the number of turns, with the
result that the signal can be increased, perhaps by an order of
magnitude.  That would leave only media noise and tracking accuracy
as the limiting factors for an order of magnitude improvement in
areal density.

      In a shielded magnetore...