Skip to ContentSkip to Navigation
Part of University of Groningen
Science LinXScience Linx News

Physicists 'freeze time' to create data storage

26 August 2014

Researchers from the FOM Foundation and University of Groningen have found a way to preserve spin information for much longer than previously possible. They isolated the spin information from the influence of the outside world in a nanoscale graphene device, in which they can easily manipulate the information with electric fields. This feature makes their device an attractive candidate for future computer data storage and for logic devices based on spins. The researchers published their results online on 22 August 2014 in Physical Review Letters.

prof. Bart van Wees
prof. Bart van Wees

(source: FOM press release)

The nanoscale device consists of a flake of graphene (a one-atom-thick layer of carbon) which is protected from the environment by stacked insulating layers of boron nitride. Electrons inside the graphene carry information: they each have a spin value (up or down), which is determined by the direction of their intrinsic magnetic moment. The spin values can be considered as computer bits, which can be used to transfer or store information.

A challenge is that electron spins usually lose their values over time (the spin relaxation time), which causes information to be lost. In graphene, this usually takes about 0.2 nanoseconds (one nanosecond is a billionth of a second). However, with their protected device, the researchers managed to increase the spin relaxation time in graphene to more than 2 nanoseconds.

Figure 1 – Device schematics, Figure 2 – Optical microscope image
Figure 1 – Device schematics, Figure 2 – Optical microscope image

Electric fields
So far, physicists could only change the value of spins in graphene (and therefore the value of the 'bits') by using magnetic fields. Using two gate electrodes, the researchers now managed to manipulate the spin information in their device with electric fields instead. Since electric fields are much easier to generate in nanoscale devices, these results pave the way to future spintronic devices based on graphene.

Spintronics
In the field of spintronics (which stands for spin and electronics), spin is used to convey information instead of electrical charges. Spin based devices have lower power consumption and are less volatile when compared to charge based ones. For this reason spintronic devices have been considered as an alternative for computer components, for instance in memory technologies like M-RAM and STT-RAM.


Reference:
Controlling spin relaxation in hexagonal BN-encapsulated graphene with a transverse electric field , M.H.D. Guimarães, P.J. Zomer, J. Ingla-Aynés, J.C. Brant, N. Tombros and B.J. van Wees, Phys. Rev. Lett. 113, DOI: 10.1103/PhysRevLett.113.086602 .

Last modified:10 June 2015 2.56 p.m.
printView this page in: Nederlands

More news

  • 15 May 2019

    Academy Medal for Trudy Dehue

    Trudy Dehue, scientific sociologist, author and emeritus professor of the University of Groningen, will receive the Academy Medal from the Royal Netherlands Academy of Arts and Sciences (KNAW). The Academy Medal is awarded every other year to individuals...

  • 15 May 2019

    Van Rijn advice hits UG hard

    The advice from the Van Rijn committee concerning the funding of higher education has heavy consequences for the UG as a broad-based classical university. The proposed redistribution of funds in favour of technical sciences is at the expense of degree...

  • 14 May 2019

    Number of children with type 1 diabetes doubled

    The number of children who are annually diagnosed with type 1 diabetes has doubled over the last 30 years. This is one of the conclusions of the PhD thesis written by Angelien Spaans-Hummelink, who works as a paediatrician at the diabetes clinic at...