London, Jan 27 (ANI): Physicists at Stanford University have produced the world's smallest lettering, which is just 1.5 nanometers (nm) tall, with the help of a molecular projector.
According to a report in New Scientist, the new letters are around a third of the size of the atomic letters made in 1990 by Donald Eigler and Erhard Schweizer at IBM.
The pair used a scanning tunneling microscope (STM) to push 35 xenon atoms across a nickel surface and spell out the company's name in letters just 5 nm tall.
A year later, researchers at Japanese firm Hitachi set the record for microscopic calligraphy. Their 1.5-nanometre-tall letters were chiseled into a molybdenum disulphide crystal, again using an STM.
Now, Christopher Moon and Hari Manoharan's team at Stanford University have equalled Hitachi's record using a holographic variation on the IBM technique.
They started with a similar setup to the IBM team, using a scanning tunneling microscope to position individual carbon monoxide molecules on a copper surface. However, the atoms are arranged in a complicated circular pattern with a void in the middle.
The team then sent a flow of electrons through the copper, some of which ripple across its surface as waves.
The ripples scatter off any carbon monoxide molecules they meet and interfere to project holographic patterns into the central clearing, which can take on a particular shape.
The researchers wrote a computer program that works out how to arrange the carbon monoxide molecules such that they scatter electrons into waves of a particular shape.
The software also demonstrated how varying the energy of the electrons could produce different shapes from the same pattern of molecules.
Reproducing some of these patterns for real using the STM has so far produced an "S", a "U" and an "SU" pair, as small as 1.5 nm high.
According to the researchers, being able to write information on such tiny scales could lead to new ways to pack large amounts of data into small spaces. (ANI)