# Shot noise in ultrathin superconducting wires

## TL;DR

This paper investigates how quantum phase slips cause voltage fluctuations in ultrathin superconducting wires, revealing that shot noise depends on measurement setup and diminishes at high frequencies in long wires.

## Contribution

It introduces a theoretical analysis of shot noise in superconducting nanowires using the Keldysh technique and phase-charge duality, highlighting measurement-dependent effects.

## Key findings

- Shot noise depends on the measurement setup.
- In long wires, shot noise power decreases with frequency.
- Shot noise vanishes beyond a threshold frequency at zero temperature.

## Abstract

Quantum phase slips (QPS) may produce non-equilibrium voltage fluctuations in current-biased superconducting nanowires. Making use of the Keldysh technique and employing the phase-charge duality arguments we investigate such fluctuations within the four-point measurement scheme and demonstrate that shot noise of the voltage detected in such nanowires may essentially depend on the particular measurement setup. In long wires the shot noise power decreases with increasing frequency $\Omega$ and vanishes beyond a threshold value of $\Omega$ at $T \to 0$