In what is considered a breakthrough in computing hardware, a team of scientists from Glasgow has proposed a way to harvest molecules and construct nano-sized non-volatile (permanent) storage devices, also known as flash memory devices. In a letter published in Naturetoday (November 20), Christoph Busche of WestCHEM School of Chemistry, University of Glasgow, and 12 others have written about their efforts to engineer molecular flash memory using nanoscale polyoxometalate clusters instead of the conventional metal-oxide semiconductor (MOS) devices.
The challenge
It is a great challenge to reduce the size of conventional MOS flash memories to sizes below ten nanometres. This poses a problem when one tries to build small flash memory devices. Hence other options have been pursued for quite some time, including those using proteins and other molecules. However, using these molecular memories involved integrating them with the MOS technologies, which was proving to be difficult and several candidates had been tried and found wanting in this attempt. The Glasgow group, headed by Leroy Cronin, has found a suitable candidate in the polyxometalate molecules.
When such a molecule is doped with the selenium derivative [(Se(IV)O)] a new type of oxidisation state (5+) is observed for the selenium. This new oxidation state can be observed at the device level, and this can be used as a memory.
Device simulation
The authors demonstrate this using a device simulation. Their work suggests a route to building molecular flash memory devices.
Flash memory is in everyday usage now. It is used in digital cameras, USBs and various other places. Unlike a computer’s RAM, which is volatile — meaning that the memory stored in it will dissipate once power supply is broken — a flash memory can retain what is written on it even when power supply is discontinued. For that reason it is called a non-volatile memory. So long, flash memories have been constituted using MOS technologies. This paper now suggests a new way of going beyond its nanoscale limitations.
Two new subatomic particles discovered
The particles were predicted to exist by the quark model but had never been seen before. A related particle was found by the CMS experiment at CERN in 2012.
Two new subatomic particles that could widen our understanding of the universe have been discovered, scientists at CERN announced on Wednesday.
The collaboration for the LHCb experiment at CERN’s Large Hadron Collider discovered the two new particles belonging to the baryon family.
A baryon is a composite subatomic particle made up of three quarks.
The particles were predicted to exist by the quark model but had never been seen before. A related particle was found by the CMS experiment at CERN in 2012.
Like the well-known protons that the LHC accelerates, the new particles are baryons made from three quarks bound together by the strong force.
The types of quarks are different, though: the new particles both contain one beauty (b), one strange (s), and one down (d) quark, CERN said in a statement.
Thanks to the heavyweight b quarks, they are more than six times as massive as the proton. But the particles are more than just the sum of their parts: their mass also depends on how they are configured.
“Nature was kind and gave us two particles for the price of one,” said Matthew Charles of the CNRS’s LPNHE laboratory at Paris VI University.
As well as the masses of these particles, the research team studied their relative production rates, their widths — a measure of how unstable they are — and other details of their decays.
The results match up with predictions based on the theory of Quantum Chromodynamics (QCD), researchers said.
QCD is part of the Standard Model of particle physics, the theory that describes the fundamental particles of matter, how they interact and the forces between them.
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