• Question: what happens if you split an electron?

    Asked by liam25 to Alan, Caspar, Diana, Murray, Sarah on 17 Mar 2011 in Categories: . This question was also asked by 09walshcou.
    • Photo: Caspar Addyman

      Caspar Addyman answered on 15 Mar 2011:

      I think you will win an nobel prize because as far as I know nobody has ever been able to do so yet. 🙂

      Scientists have been able to collide an electron into a positron (which is an anti-electron). When you do this they annihilate each other in a bright flash of energy and particles. the number and type of particles depends upon how much energy there is to release.. which depends upon how fast the electron and positron were going when they collided.

    • Photo: Murray Collins

      Murray Collins answered on 15 Mar 2011:

      Hi,

      First thing to say is that I am not a physicist, so it is not my area. But a very intriguing question. Particle physics is utterly fascinating! ..

      What I have read about electrons suggest that you can’t know where an electron is and how fast it is going at the same time, which is called Heisenberg’s uncertainty principle. This is pretty mind boggling, and would make one of the little fellas quite tough to catch! But seriously I think they are treated as fundamental particles, which as you probably know means that they are thought to not be made up of anything else, any other particle. That means that they are a fundamental building block of other larger building blocks in the universe.

      When people talk about splitting the atom, they often mean nuclear fission, which occurs when the nucleus of an atom splits into smaller nuclei, after colliding with a neutron. This can cause a chain reaction, because one nucleus splitting releases neutrons which ‘split’ the nuclei of the surrounding atoms, which releases more neutrons and so on and so on. This can release a huge amount of energy, and so is a process used in thermonuclear weapons and power stations.

      I guess since you asked the question you already knew all this. But you have stumped me – I don’t know! All I can say about the electron is that if something is not made up of anything but one unit of itself, and nothing else, then I cannot conceive of how it could be split into component parts, because that would require the electron be made of more than one component parts to allow it to be ‘split’.

      If you could send me your thoughts on the division of an electron I would be very impressed! It’s a head spinner. You made me sit back and think there. Nice one!

    • Photo: Alan Winfield

      Alan Winfield answered on 16 Mar 2011:

      Well I’m not a quantum physicist but – as far as I know – electrons can’t be split. Unlike protons and neutrons which can, I understand, be split into even smaller things called quarks. So electrons have no smaller particles inside them.

    • Photo: Sarah Thomas

      Sarah Thomas answered on 17 Mar 2011:

      Well a team of scientists from Cambridge and Birmingham managed to split electrons in 2009 (i think).

      Electrons, which can’t be split individually, can divide into two new particles called spinons and holons when they crowded into in a narrow “quantum” wire.

      While single electrons seem to be impossible to break apart, this does not seem to be the case when electrons are brought together. Instead, the like-charged electrons repel each other and need to modify the way they move to avoid getting too close to each other. In ordinary metals this does not usually make much difference to their behavior. However, if the electrons are put in a very narrow wire the effects are exacerbated as the electrons find it much harder to move past each other and eventually they fall apart into spinons and holons.

      I think they are now researching ways to control these particles as we do electrons in electronic devices like ipods.

Comments

  • Photo: Alan

    Alan commented on :

    Wow thanks Sarah – I hadn’t heard of spinons and holons before. Amazing.

  • Photo: Murray

    Murray commented on :

    Thanks Sarah! I’ve just been searching the journals and found the reference:

    Jompol et al. Probing Spin-Charge Separation in a Tomonaga-Luttinger Liquid
    Science 31 July 2009:Vol. 325 no. 5940 pp. 597-601

    Abstract:
    In a one-dimensional (1D) system of interacting electrons, excitations of spin and charge travel at different speeds, according to the theory of a Tomonaga-Luttinger liquid (TLL) at low energies. However, the clear observation of this spin-charge separation is an ongoing challenge experimentally. We have fabricated an electrostatically gated 1D system in which we observe spin-charge separation and also the predicted power-law suppression of tunneling into the 1D system. The spin-charge separation persists even beyond the low-energy regime where the TLL approximation should hold. TLL effects should therefore also be important in similar, but shorter, electrostatically gated wires, where interaction effects are being studied extensively worldwide.

    Liam 25 – I wish I had more time to keep up with what is going on in each area of science!

  • Photo: Sarah

    Sarah commented on :

    Yeah pretty amazing isn’t it? I remember being taught in school that an electron was the smallest thing in the whole universe. You have to admire the person that woke up one morning and said “I am going to try and split an electron, watch this space!!” Isn’t that crazy?

  • Photo: Caspar

    Caspar commented on :

    wow.. the universe keeps getting stranger.