A moving electron has both electric and magnetic fields that are perpendicular to its velocity direction. Does the electric field create a torque on the electron? If so what is that torque? Does it cause the electron to spin? Is the torque quantized? A recent study reveals that the torque acting on a charge in presence of an electric field is T=[qE/(mc)] hbar
Is it possible at quantum level to think of an electron as an extended object ( as a dumbbell) of two charges each with charge e/2 at a distance equals to the Compton wavelength?
Arbab,
No, the spin of the electron cannot be treated as an actual mechanical rotation: it is quantized to only two values and cannot be changed through a common-sense-like process.
There is no evidence to consider the electron as an extended object - all scattering experiments so far indicate a point-like nature.
You happen to be entertaining a similar question that I am also looking at. I will definitely come back to you on this one ...
Dear Golden,
I have also found that a torque parallel to the electric field direction sets the charge into rotation. Moreover, the charge (electron) appears to have a dipole moment= q/2 X Compton wavelength. It seems the charge extends over a distance equals to Compton wavelength =hbar/mc . Moreover, the torque is found to be quantized, T=(qE/mc) hbar !
Dear Arbab,
Would you please explain? Why do you expect the electron to have a dipole moment?
I think the dumbbell you described cannot have a dipole moment about its center.
Arbab,
>Moreover, the charge (electron) appears to have a dipole moment
Can you please indicate an experiment that demonstrates this?
Whilst it is predicted that there may be a non-zero EDM, I know of no evidence for it.
In fact the zittery motion of the electron, as shown by Schrodinger has an amplitude of Compton wavelength lambda=hbar/(mc). This implies that thee electron is not a point-like particle. If it is so, then why the electron not have an electric dipole moment. At the experimental level I don't know of any experiment showing this, but theoretically it is possible. Its value is 3.08 X 10^-33 Cm.
An electron moving in an electric field experiences a torque because the movement causes a motional magnetic field in the rest frame of the electron. The B-field then interacts with the magnetic dipole moment of the electron.
To the best of our knowledge, the electron has no measurable electric dipole moment. The Standard Model predicts something on the order of 10^(-38) e\cdot cm but the lowest experimental limit is on the order of 10^(-26) e\cdot cm. An EDM (parallel to the spin) would violate P- and T-symmetry and hence also CP.
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