| dc.description.abstract | Bell-diagonal states are extremely important for understanding the dynamics and applications
of some quantum resources. Quantum properties such as steering, entanglement,
and coherence, among others, can be used as resources in quantum computing.
Because of this, we believe it is necessary to understand the preparation of these states.
We create an adjustable quantum circuit, which we implement on the International
Business Machines (IBM) quantum computer. These computers are an excellent possibility
for carrying out experiments like this. We implement the circuit on three different
quantum chips that are available on the online platform. As an example, we measure
non-locality, steering, entanglement, discord and non-local coherence for Werner states,
which are a special type of the Bell-diagonal. We compare the theoretical results
with the experimental data. We note the harmful effect that noise can have on quantum
circuits, bringing undesirable decoherence effects to the system. We model noise in a
simple way, using two quantum channels, amplitude damping and phase damping. We
investigate the direct relationship between measures of discord and entanglement, as
well as the sudden change of discord. But, even carrying out these tests on several
quantum chips, it was not possible to carry out such verification with great clarity. On
the other hand, the great importance of Bohr’s Complementarity Principle for Quantum
Mechanics is well known. However, the search for quantifiers to measure wave
or particle characteristics, in a quantum system, has always been very intense. Recently,
a formalism was developed based on basic properties of the density matrix
( 0; Tr = 1). We use the IBM quantum computer to check the complementarity relationships
based on these properties. We calculate quantum coherence, predictability
and quantum correlations for a particular class of quantum states of one qubit and also
for random quantum states of one, two and three qubits. We note that for both cases,
the interaction of the system with the environment, and the consequent creation of correlation,
generates a decrease in the sum of quantum coherence and predictability but
which is compensated by the increase in quantum correlations between system and environment. | |
