Physicists investigate electron fractionalization into not two, but three components

Aug 12, 2010 by Lisa Zyga feature

One of the many intriguing puzzles in physics is the strange behavior of the electron as it fractionalizes into two separate quasiparticles. These quasiparticles, called spinons and chargons (or holons), carry the electron’s spin and charge, respectively. In a new study, physicists Cenke Xu and Subir Sachdev of Harvard University have investigated this phenomenon, called spin-charge separation, and have developed a model that unifies two previous theories to propose a more complete electron fractionalization process.

In order for electrons to fractionalize, many of them must be tightly confined so that they repel each other. In trying to stay apart, the electrons modify how they behave so that their magnetism (which is associated with spin) and charge separate into the two new quasiparticles. In condensed matter physics, quasiparticles are phenomena of groups of particles that behave as if they were particles. Physicists first observed spinons and holons in 2009 by confining electrons in a quantum wire and detecting how in a nearby metal could tunnel into the by splitting into the two quasiparticles.

One unsolved part of electron fractionalization involves figuring out what happens to an electron’s Fermi statistics after spin-charge separation. Fermi statistics describe the properties of all particles that obey the Pauli Exclusion Principle, which says that no two of these particles can occupy the same . In the Standard Model, these particles include all the fermions, one of which is the electron. The question that physicists ask is, when the electron fractionalizes into its spin and charge, where do its Fermi statistics go?

As Xu and Sachdev explain in their new study, there are two main answers to this question. Put simply, the Fermi statistics have previously been proposed to be either with the spin or with the charge. But Xu and Sachdev suggest that these seemingly divergent possibilities can be unified into one picture. The physicists suggest that the electron fractionalizes into not just two, but three components that carry the electron’s spin, charge, and Fermi statistics. While spinons and chargons (or holons) are the first two carriers, the Fermi statistics are carried by a Majorana fermion. The physicists also illustrated these ideas on a honeycomb lattice to demonstrate how the proposal works.

“A central problem in quantum physics is understanding the varieties of exotic quantum states of many-electron systems: their long-range and the nature of their quasiparticle excitations,” Sachdev told PhysOrg.com. “We show that most previous proposals can be unified under a single theory in which the central quasiparticle is a Majorana particle which carries only the Fermi statistics of the electron, but neither its spin nor its charge. Our theory leads to new types of quantum many-electron states, and also provides an improved and unified understanding of the previous disparate proposals.”

Interestingly, the Higgs boson or something similar to it may also play a role in Xu and Sachdev’s model. As they explain, the Majorana particle can undergo quantum transitions that are associated with the Higgs.

“Our parent Majorana liquid can exhibit quantum phase transitions to other many-electron states, in which there is qualitative change in the nature of the forces between the quasiparticles,” Sachdev said. “These forces are mediated by particles called ‘gauge bosons,’ which are similar to gauge bosons in elementary particle physics: for example, the photon that mediates the electromagnetic force, the gluon that is associated with the strong force, and the W and Z bosons that are associated with the weak force. Also in elementary particle physics, the Higgs boson is needed to make the weak force short-ranged; without it, the elementary particles would be in a new phase with a long-ranged weak force that has been presumed to exist only moments after the Big Bang. Similarly, among our many possible quantum states with different types of entanglement and quasiparticles, there are quantum transitions associated with changes in the density of bosons very similar to the Higgs boson of physics.”

Overall, a better understanding of electron fractionalization could have useful applications, such as in designing quantum computers and achieving quantum entanglement at long scales.

“Our theory leads to a deeper understanding of the different types of quantum entanglement in many-electron states at very low temperatures,” Sachdev said. “Quantum computers manipulate the entanglement in a complex manner, and we have shown there is a richer variety of available entangled states and have unified their understanding.”

Explore further: IHEP in China has ambitions for Higgs factory

More information: Cenke Xu and Subir Sachdev. “Majorana Liquids: The Complete Fractionalization of the Electron.” Physical Review Letters 105, 057201 (2010). DOI: 10.1103/PhysRevLett.105.057201

4.8 /5 (45 votes)

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Tahoma
2.5 / 5 (11) Aug 13, 2010
With careful compression of mutually repulsive electrons we can achieve their condensation into clusters of arbitrary size and nothing very strange is about it - it was predicted before forty years already.

http://en.wikiped...v_effect

Of course, these higher order geometries are gravitationally unstable in 3D space - this is why we can observe many star binaries, but ternary systems are rare. Because of flat character of ternary systems, they can be studied easier in 2D space, i.e. inside of flat sheets of graphene or inside of layered materials, where motion of electrons remains constrained with external magnetic field.

http://www.physor...630.html
KBK
3.8 / 5 (4) Aug 13, 2010
I gave him 5 stars, as right or wrong, the thought is being put into attempts. The right answers on difficult questions will always (and have always) come from areas we don't understand and are not looking directly at. That is the literal history of the development of scientific theory.

So when I catch these physorg 'baggers' coming in and hammering those who make attempts at looking into things, I see nothing less than children who have not developed themselves to any notable degree that is beyond an emotionally based schoolyard pecking order which thy have apparently disallowed themselves from escaping. And that is not science. It's far from it.

What they are doing is achieving psychological and emotional safety via exclusion as opposed to psychological and emotional risk through exploration. Two major opposing points. The risk taker and the explorer has always become the winning point, with almost zero exceptions.

The other has always been a safe (small minded) bump on a log.
Tahoma
1.9 / 5 (9) Aug 13, 2010
This is how three and four body system appears. We can see, while four body system is 3D, three body system is flat and it exists only inside of geometrically frustrated systems.

http://superstrun...body.gif
http://superstrun...body.gif
KBK
4 / 5 (2) Aug 13, 2010
Reading on the subject at wiki,

http://en.wikiped...paration

It appears that the idea of 3-d reality being 2-d sheets of infinite size and energetic oscillation interacting within their given 'spheres' is what creates a 3-d torsional spin integration of the two opposing fields at their interactive point. An innie and an outie. 3-d reality is thus a stable 'dimensional' vantage point that becomes, idealistically --- quanta. Particle and wave.

In the macroscopic world, this would implicate/create complex LCR in electron interactives with 'crystalline' solids, when under acceleration, or delta.

The above simplified explanation becomes as plausible as anything else and has the major side effect of covering all bases and potentials that are known today or even remotely suspected. Secondary bonus is that it is very simple, which means, based on prior situations and experience, it has a higher chance than most - of being correct.

Works for me.....
otto1923
2.6 / 5 (5) Aug 13, 2010
I gave him 5 stars, as right or wrong, the thought is being put into attempts. The right answers on difficult questions will always (and have always) come from areas we don't understand
I happen to agree- there are people like that. But there are also vandals who come here merely to spume about nonsense. Are you sure this is not one of them?

Observe the caliber of the denouncers and their long history of unfruitful efforts. Maybe you're wrong.
Xaero
1.5 / 5 (8) Aug 14, 2010
..there are also vandals who come here merely to spume about nonsense..
And here are also senile trolls, who prattle about Nazi, Genesis and religion bellow many articles dedicated to physics...
Ethelred
Aug 14, 2010
This comment has been removed by a moderator.
Xaero
1 / 5 (10) Aug 14, 2010
GravityPhD, sckavassalis were never my accounts. I'm always using a single login, but I cannot use a single computer.
Ethelred
3.7 / 5 (9) Aug 14, 2010
What a smoke screen. You don't even remember all your accounts. You use multiple accounts to rank yourself and others multiple times per post.

No amount of lying about why you use multiple accounts will change the way you use them. Only STOPPING that behavior will change it.

You COULD use a single account, no matter how many PCs you use if you wanted. Unless of course you are so bloody incompetent that you can't even write down you password to use on other PCs. I don't think you would admit to being that much of an idiot so that leaves yours reasons nefarious.

I can and do post from multiple PCs and I always use the same name and the same logins.

Are you admitting that I am smarter than you? More competent with PCs? Or is what the rest of us have had good to reason to conclude? The latter sure fits the evidence and nothing else does.

Ethelred
Xaero
1.9 / 5 (10) Aug 14, 2010
Are you admitting that I am smarter than you? More competent with PCs?
Of course, I've absolutely no problem with it. Why are you attacking other posters in every thread, after then? This forum is not social club. We are supposed to talk about anyons here.
Ethelred
2.6 / 5 (5) Aug 17, 2010
Why are you attacking other posters in every thread, after then?


I am not. So don't lie about it.

This forum is not social club.


It is a science forum and I discuss science issues AND forum issues. YOU are a major issue.

We are supposed to talk about anyons here.


Observe the caliber of the denouncers and their long history of unfruitful efforts. Maybe you're wrong.


Somehow that doesn't look like anyons. It looks like an attack on the people that are annoyed with your vile behavior. Which you have done many times, often while calling other posts off topic just like this time.

Oh and now there is another name you are abusing the forum with.

hodzaa

So drop the hypocrisy. You aren't fooling anyone.

Ethelred
Ethelred
3.7 / 5 (3) Aug 18, 2010
Thank you for the double downrank which, as usual, proves my point. You are a reprehensible thug who is not only using multiple logins but is using the abuse others.

So you get a bunch more ones. I do this EVERY time you abuse the system like this. It is no wonder you have idiot ideas about physics as you are completely unable to get the idea that I am attacking YOUR ABUSE of the system and have said I wouldn't have to defend myself against if you didn't abuse the system.

You will continue to get what you deserve every time you do this.

Ethelred