  Quantum Computing has been presenting major developments in the last few
years, unveiling systems with a increasing number of qubits. However,
unreliable quantum processes in universal quantum computers still represent one
of the the greatest challenges to be overcome. Such obstacle has its source on
noisy operations and interactions with the environment which introduce
decoherence to a quantum system. In this article we verify whether a tool
called Swap Test is able to identify decoherence. Our experimental results
demonstrate that the Swap Test can be employed as an alternative to a full
Quantum Process Tomography, with the advantage of not destroying the qubit
under test, under certain circumstances, as long as some modifications are
introduced.
