We propose a quantum system in which the winding number of rotations of a particle around a ring can be monitored and emerges as a physical observable. We explicitly analyze the situation when, as a result of the monitoring of the winding number, the period of the orbital motion of the particle is extended to n>1 full rotations, which leads to changes in the energy spectrum and in all observable properties. In particular, we show that in this case, the usual magnetic flux period Φ0=h/q of the Aharonov-Bohm effect is reduced to Φ0/n.
@article{arxiv.1711.01495,
title = {Indistinguishability of quantum states and rotation counting},
author = {Dmitri V. Averin and Christoph Bruder},
journal= {arXiv preprint arXiv:1711.01495},
year = {2018}
}