Browse Prior Art Database

Data Storage by Rotational Orientation of Surface Attached Molecules

IP.com Disclosure Number: IPCOM000111991D
Original Publication Date: 1994-Apr-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 66K

Publishing Venue

IBM

Related People

Brown, CA: AUTHOR [+3]

Abstract

Recently an approach to data storage was described which uses a low temperature STM to relocate atoms on a single crystal surface. Herein is described a method for storing information in the orientation of a molecular rather than its position. Readout of the stored information is accomplished by STM, AFM or optical techniques.

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Data Storage by Rotational Orientation of Surface Attached Molecules

      Recently an approach to data storage was described which uses a
low temperature STM to relocate atoms on a single crystal surface.
Herein is described a method for storing information in the
orientation of a molecular rather than its position.  Readout of the
stored information is accomplished by STM, AFM or optical techniques.

      The positioning of individual atoms with a low temperature
scanning tunneling microscope has been demonstrated recently [1]  and
the use of this technique for data has been described [2,3].  In
these approaches, information is stored in the spatial pattern of
electrical conductivity.  Two configurations were described.  One
changes the conductivity by depositing an electron [2]  and the other
by depositing an atom [3].

      An alternative method described herein involves storing
information in the orientation of complex molecules rather than the
positions of electrons or atoms.  Two embodiments are described
below.

      In the first embodiment, a molecule of low symmetry is adsorbed
on a suitable site on the surface and then rotated about an axis
perpendicular to the surface using the STM tip.  The adsorbed
molecule must have both low symmetry and a barrier to rotation around
an axis perpendicular to the surface with two or more local minima.
Information is stored in the position of the molecule relative to the
substrate or to other molecules.  One molecule can have several
stable orientations or minima and, hence, can store more than one bit
of information.

      In the second embodiment, a part of the molecule, that is
farther from the substrate, is moved.  In this case, information is
stored in the relative position of the movable appendage eit...