Graphene insulators pave way for quantum computing

23 December 2013
By Tereza Pultarova
Mobile version
Share |
Researchers have changed properties of graphene making it act as a topological insulator

Researchers have changed properties of graphene making it act as a topological insulator [Credit:MIT]

American researchers have discovered how to make graphene capable of filtering electrons according to their ‘spins’, opening new possibilities for future quantum computing.

Taking advantage of the so-called Hall Effect, the team from the Massachusetts Institute of Technology (MIT), led by professors Pablo Jarillo-Herrero and Ray Ashoori managed to alter the behaviour of the wonder material making electrons with positive spins to move clockwise around the conductive edge of a graphene sheet and those with negative spins to circle anti-clockwise. The study has been published in the latest issue of the journal Nature.

“We created an unusual kind of conductor along the edge, virtually a one-dimensional wire,” said Andrea Young, a Pappalardo Postdoctoral Fellow in MIT’s physics department, explaining that segregation of electrons according to their spins is a normal feature of topological insulators. However, graphene is not normally a topological insulator.

“We’re getting the same effect in a very different material system,” Young said.

Under normal circumstanced sheets of graphene behave as normal conductors. When voltage is applied, the electric current flows throughout the two-dimensional flake. If a graphene flake is, in addition, subject to a magnetic field perpendicular to the flake itself, its behaviour changes with current flowing only along the edge and the bulk becoming an insulator. In such a situation, electric current flows only in one direction, either clockwise or anti-clockwise, depending on the orientation of the magnetic field. This phenomenon is known as the quantum Hall effect.

In the newest experiment, the MIT researchers discovered that if a second powerful magnetic field is applied, this time in the same plane as the graphene flake, electrons with different spins start moving in different directions.

“We can turn these edge states on and off,” Young said, explaining that such capability would allow creating graphene circuits and transistors, possibly paving the way for future quantum computers.

The experiment was conducted using a magnetic field of about 35 Tesla - ten times stronger than an MRI scanner - at temperatures about 0.3 degrees Celsius above absolute zero.

According to Jarillo-Herrero, the Mitsui Career Development Associate Professor of Physics at MIT, such behaviour in graphene has previously been predicted but never actually observed.

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

    Intel
    • 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 ▶

Subscribe

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

Subscribe to E&T