Writing data with lasers overcomes speed limits

11 July 2014
By Edd Gent
Mobile version
Share |
An artist's impression of a laser pulse changing a magnetic bit

An artist's impression of a laser pulse changing a magnetic bit

A new ultra-fast method of writing information to hard drives using lasers could help overcome looming limits to write speed.

Hard drive stores bits in the form of tiny magnetic domains, with the directions of the magnetic north and south poles of these domains – referred to as the magnetisation – determining whether the domain represents a binary 0 or 1.

Data is stored by changing the direction of the magnetisation of the associated bits, which is currently done using a write head to create a local magnetic field to make a bit change direction.

The stronger the field, the faster the switch takes place, but this is subject to a physical limit that has now almost been reached by current information storage technology.

"The number of bits has been growing rapidly for many years, but the write speed has hardly increased. There's a need for a new data storage technology", said Eindhoven University of Technology researcher Sjors Schellekens, the lead author of a paper in Nature Communications that presents an alternative technology.

Led by Professor Bert Koopmans, the team used ultra-fast laser pulses to generate a flow of electrons in a material which all have the same spin – a quantum-mechanical property that acts like a kind of internal compass in the electron. The resulting 'spin current' is used to change the magnetic properties of the material but at a much faster rate than current technology.

Two layers with opposite magnetisation are separated by a neutral layer. When a laser pulse strikes electrons in the upper layer it causes them to move through the material, in the direction of the second layer.

The spin of these electrons exerts a force on the spin of the electrons in the lower layer to make them rotate in the same direction, altering their magnetisation.

"The change in the magnetisation is of the order of 100 femtoseconds, which is a factor 1,000 faster than what is possible with today's technology", said Schellekens. "There was discussion among physicists about whether the generated spin current is actually able to cause the change in magnetisation. We now definitely show that this is really the case."

The method is a step towards future optical computer chips, which TU Eindhoven is currently working on – in December the university received a Dutch government grant of almost €20m to integrate photonics in computer systems.

"Our technology allows optical data to be stored in the form of magnetic bits. That offers unprecedented opportunities if you want to use light as information carrier", said Schellekens.

Latest Issue

E&T cover image 1604

"Should the UK's engineers be in or out of Europe? The IET sets out its official position on the EU referendum this week - will you agree?"


E&T jobs

  • Solutions Engineer

    Bristol Water
    • United Kingdom
    • £41,000 - 49,000

    We serve a population of over one million people and all the associated businesses in an area of 1,000 square miles centered on Bristol.

    • Recruiter: Bristol Water

    Apply for this job

  • Senior Mechanical Engineer

    Bristol Water
    • United Kingdom
    • £41,000 - 49,000

    We serve a population of over one million people and all the associated businesses in an area of 1,000 square miles centered on Bristol.

    • Recruiter: Bristol Water

    Apply for this job

  • Software Renewals Manager

    BAE Systems
    • Preston, Lancashire, England
    • Negotiable

    Software Renewals Manager Would you like to work in a resourceful and developing role within IT Services? We currently have a vacancy for a Software Renewals Manager at our site in Preston Channel Way. As a Software Renewals Manager, you will be responsi

    • Recruiter: BAE Systems

    Apply for this job

  • Technical Manager

    Aggregate Industries
    • Hulland Ward, Ashbourne
    • Attractive salary plus comprehensive benefits

    A key Technical Manager role driving product improvement and compliance with Aggregate Industries, market leader in Construction Solutions.

    • Recruiter: Aggregate Industries

    Apply for this job

  • Field Application Engineer

    • Madrid

    Responsible for giving product presentations to the customer describing how Intel products provide the optimum solution to their application.

    • Recruiter: Intel

    Apply for this job

  • Engineers and Scientists

    European Patent Office
    • Munich and The Hague
    • See job description

    We are looking for Engineers and scientists in various technical fields for our locations in Munich and The Hague.

    • Recruiter: European Patent Office

    Apply for this job

  • Director of Product Management

    EMS Recruitment Group
    • West Yorkshire
    • Circa £70,000 PA + car allowance, excellent benefits including lucrative bonus scheme

    Our client is the undoubted world leader in their field. A highly innovative and progressive specialist electro-mechanical product manufacturer....

    • Recruiter: EMS Recruitment Group

    Apply for this job

  • Electrical Engineer

    Premium job

    Scottish Prison Service
    • Edinburgh, City of Edinburgh
    • £40,654 to £48,579 plus annual supplement of £10,000

    Build Your Engineering Career. The Scottish Prison Service (SPS) is an Agency of the Scottish Government, working in partnership.....

    • Recruiter: Scottish Prison Service

    Apply for this job

  • Sales Electronics Engineer

    Premium job

    Precision Microdrives
    • London (Greater)
    • £25,000 - £30,000 starting salary, inclusive of on-target commissions.

    Precision Microdrives (PMD) is a fast growing technology company that designs, produces and trades miniature electro-mechanical mechanisms

    • Recruiter: Precision Microdrives

    Apply for this job

  • Installation and Commissioning Engineer

    Premium job

    Crest Solutions
    • Corby
    • Competitive

    You will be involved in installation, commissioning & servicing of printing and machine vision related solutions.

    • Recruiter: Crest Solutions

    Apply for this job

More jobs ▶


Choose the way you would like to access the latest news and developments in your field.

Subscribe to E&T