Semiconductor structures, low-dimensional systems, quantum phenomena

High-temperature shot noise in the single-channel Aharonov–Bohm interferometer

R. A. Niyazov^ab, I. V. Krainov^a, D. N. Aristov^abc, V. Yu. Kachorovskii<sup>a

a</sup> Ioffe Institute, 194021 St. Petersburg, Russia
^b The Petersburg Nuclear Physics Institute, The National Research Center "Kurchatov Institute", 188300 Gatchina, Russia
^c Saint Petersburg State University, 199034 St. Petersburg, Russia

Abstract: Shot noise is theoretically investigated in Aharonov–Bohm interferometers formed by single-channel spinless quantum wires. Analysis focuses on the experimentally important regime of relatively high temperatures, where thermal energy exceeds the level spacing. It is shown that quantum interference effects dramatically alter current fluctuations even when coherence suppression might be expected. The Fano factor – the ratio of shot noise power to Schottky noise – is demonstrated to exhibit sharp, periodically repeating resonances as a function of magnetic flux. For symmetric interferometers, these resonances occur at half-integer flux quanta, while geometric asymmetry leads to additional features at integer flux values. It is found that interferometers with different contact configurations can possess identical conductance but substantially different noise characteristics, enabling experimental determination of contact properties through combined measurements of conductance and noise. The obtained results allow for direct experimental verification and propose noise spectroscopy and characterization of mesoscopic devices as a powerful tool complementary to conductance measurements.

Received: 15.10.2025
Revised: 29.10.2025
Accepted: 29.10.2025

DOI: 10.61011/FTP.2025.08.62189.8623