Schwinger effect

The Schwinger effect is a predicted physical phenomenon whereby matter is created by a strong electric field.

The effect was originally proposed by Fritz Sauter in 1931[1] and further important work was carried out by Werner Heisenberg and Hans Heinrich Euler in 1936,[2] though it was not until 1951 that Julian Schwinger gave a complete theoretical description.

To understand this, note that electrons and positrons are each other's antiparticles, with identical properties except opposite electric charge.

Linear and angular momentum are conserved because, in each pair, the electron and positron are created with opposite velocities and spins.

In fact, the electron and positron are expected to be created at (close to) rest, and then subsequently accelerated away from each other by the electric field.

The original Schwinger effect of quantum electrodynamics has never been observed due to the extremely strong electric-field strengths required.

Pair production takes place exponentially slowly when the electric field strength is much below the Schwinger limit, corresponding to approximately 1018 V/m.

The rate of pair production may be significantly increased in time-dependent electric fields,[5][6][7] and as such is being pursued by high-intensity laser experiments such as the Extreme Light Infrastructure.

[8] Another possibility is to include a highly charged nucleus which itself produces a strong electric field.

[13][14][15] In June 2023, researchers at the  Ecole Normale Supérieure in Paris and their collaborators reported the quantitative measurement of the Schwinger-pair production rate in doped graphene transistors in a 1D geometry.