# Tunneling without tunneling: wavefunction reduction in a mesoscopic qubit

## TL;DR

This paper proposes a method to demonstrate wavefunction reduction in mesoscopic qubits through a transformation cycle and inequality violation, challenging traditional Schrödinger dynamics and feasible with current superconducting qubit technology.

## Contribution

It introduces a new experimental approach using a transformation cycle and inequality to directly observe wavefunction reduction in mesoscopic qubits.

## Key findings

- The proposed inequality can be violated in experiments.
- The method is feasible with existing superconducting qubit technology.
- Demonstrates wavefunction collapse without tunneling through barriers.

## Abstract

The transformation cycle and associated inequality are suggested for the basic demonstration of the wavefunction reduction in a mesoscopic qubit in measurements with quantum-limited detectors. Violation of the inequality would show directly that the qubit state changes in a way dictated by the probabilistic nature of the wavefunction and inconsistent with the dynamics of the Schr\"{o}dinger equation: the qubit tunnels through an infinitely large barrier. Estimates show that the transformation cycle is within the reach of current experiments with superconducting qubits.