Unrestricted Electron Bunching at the Helical Edge
Abstract
A quantum magnetic impurity of spin S at the edge of a two-dimensional time reversal invariant topological insulator may give rise to backscattering. We study here the shot noise associated with the backscattering current for arbitrary S . Our full analytical solution reveals that for S >1/2 the Fano factor may be arbitrarily large, reflecting bunching of large batches of electrons. By contrast, we rigorously prove that for S =1/2 the Fano factor is bounded between 1 and 2, generalizing earlier studies.
- Publication:
-
Physical Review Letters
- Pub Date:
- August 2019
- DOI:
- 10.1103/PhysRevLett.123.056803
- arXiv:
- arXiv:1903.03965
- Bibcode:
- 2019PhRvL.123e6803K
- Keywords:
-
- Condensed Matter - Mesoscale and Nanoscale Physics
- E-Print:
- 6 pages, 2 figures, Supplemental Material