Electron electric dipole moment

The electron electric dipole moment d_e is an intrinsic property of an electron such that the potential energy is linearly related to the strength of the electric field:

${\displaystyle U=\mathbf {d} _{\rm {e}}\cdot \mathbf {E} .}$

The electron's electric dipole moment (EDM) must be collinear with the direction of the electron's magnetic moment (spin). Within the Standard Model of elementary particle physics, such a dipole is predicted to be non-zero but very small, at most 10⁻³⁸ e⋅cm, where e stands for the elementary charge. The discovery of a substantially larger electron electric dipole moment would imply a violation of both parity invariance and time reversal invariance.