Eliminating electron crosstalk effects

Millions of electrons constantly enter and exit short lengths of conducting wire, generating a localized electromagnetic field outside the wire as they travel. This field can interfere with other nearby conducting wires acting like antennae, leading to a false signal, known as crosstalk.

Real signals of quantum electron antibunching — in which particles from a continuous beam should arrive at a detector simultaneously but avoid each other instead — may be hiding in false crosstalk signals, making them difficult to find. Krishnan U M et al. developed a method for correcting this crosstalk.

The authors subtracted a normalized fit of a random continuous source out of the measurement data, thereby eliminating the crosstalk effect. They tested this technique using a heated tungsten wire as their electron source, and found the antibunching signal can be corrected to better than 1%.

According to their work, crosstalk on the scale of 1% of the experimental signal can lead to an 8% antibunching dip in coincidence, so corrections for future electron imaging applications are needed.

“I like to say that where electron microscopy ends is where electron correlation imaging starts,” said author Herman Batelaan. “Electron correlation is two-particle physics, where the uncertainty relation tells you how close electrons have to be to get antibunching.”

Batelaan emphasized that the work can be applicable beyond those studying quantum electron antibunching, as the crosstalk phenomenon is not often considered and may be more widespread.

“It could be that other researchers, like us, might miss this effect and get compromised data,” he said. “So we hope that our paper serves the scientific community in a larger context than only people hunting for electron quantum degeneracy.”

Source: “A study of crosstalk in quantum degeneracy coincidence measurements,” by Arjun Krishnan U. M., Raul Puente, M. A. H. B. Yusoff, Sam Keramati, and Herman Batelaan, Review of Scientific Instruments (2025). The article can be accessed at https://doi.org/10.1063/5.0250020 .