Single atoms become teensy data storage devices | Science News for Students

Single atoms become teensy data storage devices

Each bit of data is encoded using an atom’s magnetic spin
Apr 7, 2017 — 7:10 am EST
atom-magnet

Scientists have just shown they can store data in individual atoms of holmium (shown above). Each digital bit of data is encoded using the atom’s magnetic field.

IBM

NEW ORLEANS, La.— ­The tiniest electronic gadgets have nothing on this new device to store data. It encodes each bit of data using the magnetic field of a single atom. This makes for extremely compact data storage. The rub: So far, researchers have stored only two bits of data this way.

A bit is the smallest unit of data, equal to a zero or one. “If you can make your bit smaller, you can store more information,” says Fabian Natterer. He’s a physicist at the École Polytechnique Fédérale de Lausanne in Switzerland. Natterer described his team’s achievement March 16 at a meeting, here, of the American Physical Society. His group also shared their results in the March 9 Nature.

The researchers created the super-tiny magnetic bits using atoms of the metal holmium.  They placed the atoms onto a surface of magnesium oxide. The direction of each atom’s magnetic field served as a zero or one. Which it was depended on whether its north pole was pointing up or down.

Using a special microscope, the scientists could flip an atom’s magnetic orientation. This would switch a bit from 0 to 1 — or back again. To read out the data, the researchers measured the electric current running through the atom. That current will depend on the orientation of the magnetic field.

To ensure that such a change in current was due to a flipping of the atom’s magnetic field, the team added bystander atoms of iron. (This allowed the scientists to check how the holmium atoms’ magnetic fields had affected the iron atoms.)

The new system could lead to new hard drives that store data much more densely than has been possible. Today’s data systems need 10,000 atoms or more to store a single bit of information.

Natterer also hopes to use these mini magnets to construct materials with fine-tuned magnetic properties. They could be built up one atom at a time. “You can play with them,” he explains. He likened them to Lego blocks.

Power Words

(for more about Power Words, click here)

atom     The basic unit of a chemical element. Atoms are made up of a dense nucleus that contains positively charged protons and uncharged neutrons. The nucleus is orbited by a cloud of negatively charged electrons.

bit     (in computer science) The term is short for binary digit. It has a value of either 0 or 1.

current     A fluid — such as of water or air — that moves in a recognizable direction. (in electricity) The flow of electricity or the amount of electricity moving through some point over a particular period of time.

data     Facts and/or statistics collected together for analysis but not necessarily organized in a way that gives them meaning. For digital information (the type stored by computers), those data typically are numbers stored in a binary code, portrayed as strings of zeros and ones.

electric current     A flow of electric charge — electricity — usually from the movement of negatively charged particles, called electrons.

encode     (adj. encoded) To use some code to mask a message.

field     (in physics) A region in space where certain physical effects operate, such as magnetism (created by a magnetic field), gravity (by a gravitational field), mass (by a Higgs field) or electricity (by an electrical field).

hard drive     A device that reads and writes — and hence can store — digital data onto a rigid magnetic disk.

holmium     An element having the atomic number 67. Discovered in 1878, the nontoxic, silvery metal is extremely stable, with a melting point of 1472° Celsius (2682° Fahrenheit). It gets its name from the Latin for Stockholm (one of its discoverers was a Swede). It may be used in alloys to make magnets. It also finds use in nuclear reactors to help control their power-releasing chain reactions.

information     (as opposed to data) Facts provided or trends learned about something or someone, often as a result of studying data.

iron     A metallic element that is common within minerals in Earth’s crust and in its hot core. This metal also is found in cosmic dust and in many meteorites.

magnesium     A metallic element that is number 12 on the periodic table. It burns with a white light and is the eighth most abundant element in the Earth’s crust.

magnetic field     An area of influence created by certain materials, called magnets, or by the movement of electric charges.

oxide     A compound made by combining one or more elements with oxygen. Rust is an oxide; so it water.

physical     (adj.) A term for things that exist in the real world, as opposed to in memories or the imagination. It can also refer to properties of materials that are due to their size and non-chemical interactions (such as when one block slams with force into another).

physicist     A scientist who studies the nature and properties of matter and energy.

Citation

Journal:​ F. Natterer et al. Storing information in single atom magnets. American Physical Society March Meeting, New Orleans, March 16, 2017.

Journal:​ F.D. Natterer et al. Reading and writing single-atom magnetsNature. Vol. 543, March 9, 2017, p. 226. doi: 10.1038/nature21371.