The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 24, 2002
Filed:
Feb. 13, 2001
Masaaki Tanaka, Saitama-ken, JP;
Toshiaki Hayashi, Tokyo, JP;
Japan Science and Technology Corporation, Kawaguchi, JP;
Abstract
A ferromagnetic double quantum well tunneling magnetoresistance device is disclosed that utilizes a two-dimensional electron (positive hole) system to obtain an infinitely great magnetoresistance ratio. Also disclosed are a sensitive magnetic sensor and a nonvolatile storage device derived from that device. In structural terms of the device, a first and a second quantum well layer of ferromagnetic material ( ) in each of which the quantum confinement for carriers is established in a two-dimensional electron (positive hole) state are each sandwiched between a pair of barrier layers of nonmagnetic material ( ) through which the carriers can tunnel. The first and second quantum well layers ( ) have a difference in coercive force so that when an external magnetic field is applied thereto only one of them may be reversed in the direction of magnetization. As a result, if magnetizations of the two quantum wells are parallel to each other, tunneling is allowed to occur, and if they are antiparallel to each other, tunneling is inhibited. A infinitely great tunneling magnetoresistance ratio is thereby obtained.