nLab fictitious gauge field

Contents

Contents

Idea

In general the term fictitious gauge field could refer to any auxiliary gauge field. Specifically the term is used:

For anyon statistics

A model for anyon statistics via otherwise free fermions in 2d, mutually interacting through a flat “fictitious gauge field” has been proposed in Arovas, Schrieffer, Wilczek & Zee 1985, developed in Chen, Wilczek, Witten & Halperin 1989. This model has been advertized in several early reviews (e.g. Wilczek 1990, §I.3, Wilczek 1991, but seems not to have been developed much since:

The model regards anyons as a priori free fermions, but equipped now with a non-local mutual interaction via a “fictitious gauge field” (CWWH89, §2), in that each of the particles is modeled as the singular source of a flat circle connection (a vector potential with vanishing field strength), which hence exerts no Lorentz force but has the effect that globally each particle is subject to the same Aharonov-Bohm effect as would be caused by a tuple of infinite solenoids piercing through each of the other particle’s positions.

For emphasis, from CWWH89, p. 359:

Here the particles are to be regarded (in the absence of interactions) as fermions; the interaction then makes them anyons with statistical parameter θ=π(11/n)\theta = \pi(1 - 1/n).

It follows that (quoting from Fröhlich, Gabbiani & Marchetti 1990, p. 20):

If θ/12\theta \in\!\!\!\!\!/ \frac{1}{2}\mathbb{Z} the Hilbert space of anyon wave functions must be chosen to be a space of multi-valued functions with half-monodromies given by the phase factors exp(2πiθ)exp(2 \pi \mathrm{i} \theta). Such wave functions can be viewed as single-valued functions on the universal cover M˜ n\widetilde M_n of M nM_n [[the configuration space of points]].

Incidentally, the quasi-particle-excitations of (or in) a gas of such Aharonov-Bohm phased anyons are argued to be vortices (CWWH89, p. 457):

we are led to conclude that in anyon superconductivity, charged quasi-particles and vortices do not constitute two separate sorts of elementary excitations - they are one and the same.

References

For anyon statistics

Review in:

In solid state physics

Fictitious gauge fields:

Last revised on June 4, 2022 at 12:49:32. See the history of this page for a list of all contributions to it.