4 ms·

That explains having a 50% chance of seeing an electron somewhere, not seeing an entity of charge 1/2. It's like a weather report saying there's a 50% chance

That explains having a 50% chance of seeing an electron somewhere, not seeing an entity of charge 1/2. It's like a weather report saying there's a 50% chance of rain doesn't mean you're going to see little raindrops cut in half.

gradschoolfail 2y ago
If you look at the experiments, they don’t mention observing a single entity of fractional charge, it is always in terms of aggregate behavior under EM fields: conductance(1) inferred from shot noise (2), or density (3) (1) https://arxiv.org/pdf/0912.4868 https://arxiv.org/pdf/0912.4868 (2) https://n.ethz.ch/~marnikm/files/shotNoise.pdf https://n.ethz.ch/~marnikm/files/shotNoise.pdf (3) https://www.researchgate.net/profile/Gerhard-Abstreiter/publication/8400215_Localization_of_Fractionally_Charged_Quasi-Particles/links/0fcfd5086ea87c7bbd000000/Localization-of-Fractionally-Charged-Quasi-Particles.pdf?origin=publication_detail&_tp=eyJjb250ZXh0Ijp7ImZpcnN0UGFnZSI6InB1YmxpY2F0aW9uIiwicGFnZSI6InB1YmxpY2F0aW9uRG93bmxvYWQiLCJwcmV2aW91c1BhZ2UiOiJwdWJsaWNhdGlvbiJ9fQ https://www.researchgate.net/profile/Gerhard-Abstreiter/publ... Personally, I find it curious that people talk about detecting single photons, but in these fractional charge experiments, nobody mentions detecting a single quasiparticle. As for the math, nobody says it outright, or even in a single paragraph, but a fractional charge (“filling fraction”) of p/q does correspond to p “normal” charges distributed over q degenerate states (q=2 equivalent locations I used in the naive example) https://xgwen.mit.edu/sites/default/files/documents/topWN.pdf https://xgwen.mit.edu/sites/default/files/documents/topWN.pd...
- zmgsabst 2y ago
  > Personally, I find it curious that people talk about detecting single photons, but in these fractional charge experiments, nobody mentions detecting a single quasiparticle. You detect a single photon when it perturbs an apparatus like a photon multiplier; you detect a single quasiparticle when it perturbs a split stream of electrons. The apparent difference is that photons can travel through free space and strike such an apparatus from afar; while quasiparticles definitionally cannot. However, I’ve read about experiments that measure a single anyon on a dot by wrapping electron interferometry around it, which is measuring the lone quasiparticle on that dot. So I don’t follow your point.
  - gradschoolfail 2y ago
    Thank you for keeping me on my feet! You probably mean the following (note the nuance and date of the first one): https://arxiv.org/pdf/2403.12139.pdf https://arxiv.org/pdf/2403.12139.pdf https://www.nature.com/articles/s41567-020-1019-1 https://www.nature.com/articles/s41567-020-1019-1 I still think my point, originally about 1 electron split into 2 locations, or “ends” of string (but devolving to a complaint about casual ignorance of the central issue in publications) hasn’t been completely destroyed, because here you are measuring interference of 2 anyons, somewhat like measuring the interference of a photon “with itself” in a double split experiment. The broader point could be that the effect of a single photon is “localized”, but here to see the effect, you have to move 1 anyon in a “complete path” around the other, recalling the Feynman/Dirac belt in my top level comment, a trick I said an adult should try to correct me with :)
marcosdumay 2y ago
There is only a difference if you observe the position. When interactions happen only between particles that are all spread through that same space, both look the same.

gradschoolfail 2y ago

If you look at the experiments, they don’t mention observing a single entity of fractional charge, it is always in terms of aggregate behavior under EM fields: conductance(1) inferred from shot noise (2), or density (3) (1) https://arxiv.org/pdf/0912.4868 https://arxiv.org/pdf/0912.4868 (2) https://n.ethz.ch/~marnikm/files/shotNoise.pdf https://n.ethz.ch/~marnikm/files/shotNoise.pdf (3) https://www.researchgate.net/profile/Gerhard-Abstreiter/publication/8400215_Localization_of_Fractionally_Charged_Quasi-Particles/links/0fcfd5086ea87c7bbd000000/Localization-of-Fractionally-Charged-Quasi-Particles.pdf?origin=publication_detail&_tp=eyJjb250ZXh0Ijp7ImZpcnN0UGFnZSI6InB1YmxpY2F0aW9uIiwicGFnZSI6InB1YmxpY2F0aW9uRG93bmxvYWQiLCJwcmV2aW91c1BhZ2UiOiJwdWJsaWNhdGlvbiJ9fQ https://www.researchgate.net/profile/Gerhard-Abstreiter/publ... Personally, I find it curious that people talk about detecting single photons, but in these fractional charge experiments, nobody mentions detecting a single quasiparticle. As for the math, nobody says it outright, or even in a single paragraph, but a fractional charge (“filling fraction”) of p/q does correspond to p “normal” charges distributed over q degenerate states (q=2 equivalent locations I used in the naive example) https://xgwen.mit.edu/sites/default/files/documents/topWN.pdf https://xgwen.mit.edu/sites/default/files/documents/topWN.pd...

zmgsabst 2y ago
> Personally, I find it curious that people talk about detecting single photons, but in these fractional charge experiments, nobody mentions detecting a single quasiparticle. You detect a single photon when it perturbs an apparatus like a photon multiplier; you detect a single quasiparticle when it perturbs a split stream of electrons. The apparent difference is that photons can travel through free space and strike such an apparatus from afar; while quasiparticles definitionally cannot. However, I’ve read about experiments that measure a single anyon on a dot by wrapping electron interferometry around it, which is measuring the lone quasiparticle on that dot. So I don’t follow your point.
- gradschoolfail 2y ago
  Thank you for keeping me on my feet! You probably mean the following (note the nuance and date of the first one): https://arxiv.org/pdf/2403.12139.pdf https://arxiv.org/pdf/2403.12139.pdf https://www.nature.com/articles/s41567-020-1019-1 https://www.nature.com/articles/s41567-020-1019-1 I still think my point, originally about 1 electron split into 2 locations, or “ends” of string (but devolving to a complaint about casual ignorance of the central issue in publications) hasn’t been completely destroyed, because here you are measuring interference of 2 anyons, somewhat like measuring the interference of a photon “with itself” in a double split experiment. The broader point could be that the effect of a single photon is “localized”, but here to see the effect, you have to move 1 anyon in a “complete path” around the other, recalling the Feynman/Dirac belt in my top level comment, a trick I said an adult should try to correct me with :)

marcosdumay 2y ago

There is only a difference if you observe the position. When interactions happen only between particles that are all spread through that same space, both look the same.