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 1607

"As the dust settles after the referendum result, we consider what happens next. We also look forward to an international summer of sport."

E&T jobs

  • Stakeholder Specialist (Pricing)

    National Grid
    • Leicestershire, England, Hinckley
    • Negotiable

    Stakeholder Specialist (Pricing) National Grid connects Britain with the electricity and gas that keeps homes warm and businesses powered. We are driving the agenda to provide secure and sustainable energy both now and in the future. To meet this challen

    • Recruiter: National Grid

    Apply for this job

  • Investment Strategy Analyst (Capital)

    National Grid
    • Leicestershire, Hinckley, England
    • Negotiable

    Investment Strategy Analyst (Capital)£28,185 - £31,501 plus relevant benefitsHinckley National Grid's energy network transports gas to homes and businesses all over the UK. It's an essential part of all our lives. And it needs to be continuously advanced

    • Recruiter: National Grid

    Apply for this job

  • Integrity Engineer

    National Grid
    • England, West Midlands / England
    • £41 - £526 per annum + plus relevant benefits

    Integrity Engineer£41,526 - £46,000 plus relevant benefitsWest Midlands/East Midlands National Grid's energy network transports gas and electricity to homes and businesses all over the UK. It's an essential part of all our lives. And it needs to be contin

    • Recruiter: National Grid

    Apply for this job

  • Asset Strategy Specialist

    National Grid
    • England, Hinckley, Leicestershire
    • Negotiable

    National Grid's distribution network transports gas to homes and businesses all over the UK. It's an essential part of all our lives. And it needs to be continuously advanced and enhanced to meet increasing demand whilst embracing new energy solutions. Th

    • Recruiter: National Grid

    Apply for this job

  • Senior Engineer, Network Equipment

    Energy Networks Association
    • Westminster
    • £49-58k per annum, dependent on experience

    Manage issues and working groups relating to all types of equipment and assets used on the UK Transmission and Distribution Networks.

    • Recruiter: Energy Networks Association

    Apply for this job

  • Programme Manager, Network Resilience

    Energy Networks Association
    • Westminster
    • Competitive salary, dependent on experience

    Co-ordinate the network resilience, emergency planning and the Single Electricity Number (SEN) work in the ENA Engineering team.

    • Recruiter: Energy Networks Association

    Apply for this job

  • Operations Supervisor (Mechanical/Electrical/Instrumentation)

    National Grid
    • England, Cambridgeshire
    • £33000 - £39000 per annum

    Operations Supervisor - (Mechanical/Electrical/Instrumentation) Salary: Circa £33k - 39k dependant on experience + vehicle and great additional benefits (share scheme, pension, potential bonus).Location: Wisbech - Cambridgeshire We currently have an excit

    • Recruiter: National Grid

    Apply for this job

  • Process Controls Leader

    Premium job

    Phillips 66
    • Humber Refinery, South Killingholme, North Lincolnshire DN40 3DW
    • £60k - 75k plus extensive Compensation and benefits package, dependent upon experience

    Experienced Process Control Leader providing leadership and technical support for Oil Refinery. Extensive Compensation and benefits package.

    • Recruiter: Phillips 66

    Apply for this job

  • Regional Technical Support Manager

    Premium job

    Siemens
    • Warwick, Warwickshire

    You will be required to lead the regional Customer Services strategy and resources to maximise Customer satisfaction.

    • Recruiter: Siemens

    Apply for this job

  • Assistant Professor (Tenure Track) of Smart Building Solutions

    Premium job

    ETH Zurich
    • Zurich, Canton of Zürich (CH)

    The successful candidate is expected to develop a strong and visible research programme in the area of control and diagnostics of building systems

    • Recruiter: ETH Zurich

    Apply for this job

More jobs ▶

Subscribe

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

Subscribe to E&T