In this information age, increased storage capacity is a central challenge for science and technology. A team of German and Italian researchers has pursued this by exploring the concept of “nanostructured storage domains”.
As the scientists, led by Massimiliano Cavallini at the National Research Council (CNR) in Bologna (Italy) and Mario Ruben at the Forschungszentrum Karlsruhe (Germany), report in the journal Angewandte Chemie, they have been able to produce reliable nanopatterns of a spin-transition compound on silicon oxide chips. This is a decisive step toward a new generation of molecular storage media in which binary data are stored by the “switching” of electron spins.
Currently, computer hard drives store data by magnetizing the surface of a rotating disk. Each “storage cell” has an “address”, so that stored data can be accessed directly. To increase storage capacity, the individual magnetic domains are made smaller and smaller; we are however getting close to the limit. Thermal excitation occasionally causes some of the magnetic particles to flip in the other direction. When the domains are very small, the entire cell can rapidly lose its magnetization.
To achieve higher information density, we could change to other switchable material properties, such as the transition between two spin states. For example, iron(II) compounds can exist in either a high- or a low-spin state. “Switching” (flipping) can be controlled by changes in temperature, pressure, or electromagnetic radiation.
In addition to two distinguishable states to represent 0 and 1, data storage also requires a unique “address” for each storage location that can be identified by the optical writing and reading units of the computer. This requires an interface that makes the nanoscopic spin-state transitions of the molecular switching units compatible with the microscale instrument environment. This is possible if the spin-transition compound can be put into a highly ordered micro- or nanostructure.
By using special unconventional micro- and nanolithographic techniques, the team was able to “print” a neutral iron(II) complex onto a silicon wafer in the form of very fine lines. In this process, the nanocrystals organize themselves into a preferred orientation along the line. Furthermore, the researchers were able to transfer the pattern of a recorded CD onto a film of this iron compound. This is the first proof that it is possible to produce readable logic patterns with a spin-transfer compound.
To make the stripe structures technologically useful, the switching process must be adapted to room-temperature conditions; work on this front is already at an advanced stage.
Author: Massimiliano Cavallini, CNR, Institute for Nanostructured Materials, Bologna (Italy), http://www.bo.ismn.cnr.it/staff.php?idcur=29
Title: Micro- and Nanopatterning of Spin-Transition Compounds into Logical Structures
Angewandte Chemie International Edition 2008, 47, No. 45, 8596–8600, doi: 10.1002/anie.200802085
Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Chemists at FAU successfully demonstrate imine hydrogenation with inexpensive main group metal
22.05.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.
Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...
A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.
Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
18.05.2018 | Power and Electrical Engineering
18.05.2018 | Information Technology
18.05.2018 | Information Technology