For decades, computer chips have been shrinking thanks to a steady stream of technological improvements in processing density. Experts have, however, been warning that we'll soon reach the end of the trend known as Moore's Law, in which the number of transistors per square inch on integrated circuits doubles every year. In order to continue improving chip performance, either the material the transistors are made of — from silicon, to carbon nanotubes or graphene — or how current materials store and process information would need to change.
A much faster and more efficient method was developed to store and process information by expanding the limitations of how the flow of electricity can be used and managed. Light can induce magnetization in certain semiconductors — the standard class of materials at the heart of all computing devices today. The results could allow for a fundamentally new way to process, transfer, and store information by electronic devices that is much faster and more efficient than conventional electronics.
The finding is made possible by magnetism and a field called spintronics, which proposes to store binary information within an electron's spin direction, in addition to its charge and plasmonics, which studies collective oscillations of electrons in a material.
The researchers basically magnetized individual semiconducting nanocrystals (tiny particles nearly 10,000 times smaller than the width of a human hair) with light at room temperature. It is reportedly the first time collective motion of electrons, known as plasmon, was used to induce a stable magnetization within such a non-magnetic semiconductor material.
In manipulating plasmon in doped indium oxide nanocrystals, the findings prove that the magnetic and semiconducting properties can indeed be coupled, all without needing ultra-low temperatures (cryogens) to operate a device.