Nondestructive identification of the Bell diagonal state

TL;DR

This paper introduces a nondestructive method for identifying unknown Bell diagonal states by measuring probe qubits, preserving the original state, and details its implementation in cavity electrodynamics.

Contribution

It presents a novel nondestructive identification scheme that measures probe qubits instead of the Bell diagonal state itself, maintaining the state integrity.

Findings

The scheme allows quantum-state nondestructive identification.

It can be realized within cavity electrodynamics.

The original Bell diagonal state remains intact after measurement.

Abstract

We propose a scheme for identifying an unknown Bell diagonal state. In our scheme the measurements are performed on the probe qubits instead of the Bell diagonal state. The distinguished advantage is that the quantum state of the evolved Bell diagonal state ensemble plus probe states will still collapse on the original Bell diagonal state ensemble after the measurement on probe states, i.e. our identification is quantum-state nondestructive. It is also shown finally how to realize our scheme in the framework of cavity electrodynamics.