Alexandre M. Souza

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Irreversibility is one of the most intriguing concepts in physics. While microscopic physical laws are perfectly reversible, macroscopic average behavior has a preferred direction of time. According to the second law of thermodynamics, this arrow of time is associated with a positive mean entropy production. Using a nuclear magnetic resonance setup, we(More)
In this paper we present an analog of the Bell's inequalities violation test for N qubits to be performed in a nuclear magnetic resonance (NMR) quantum computer. This can be used to simulate or predict results for different Bell's inequalities tests, with distinct configurations and larger number of qubits. To demonstrate our scheme, we implemented a(More)
In this work we applied a quantum circuit treatment to describe the nuclear spin relaxation. From the Redfield theory, we were able to describe the quadrupolar relaxation as a computational process in the case of spin 3/2 systems, through a model in which the environment is comprised by five qubits and three different quantum noise channels. The interaction(More)
The Yang-Baxter equation is an important tool in theoretical physics, with many applications in different domains that span from condensed matter to string theory. Recently, the interest on the equation has increased due to its connection to quantum information processing. It has been shown that the Yang-Baxter equation is closely related to quantum(More)
Memoryless time evolutions are ubiquitous in nature but often correspond to a resolution-induced approximation, i.e. there are correlations in time whose effects are undetectable. Recent advances in the dynamical control of small quantum systems provide the ideal scenario to probe some of these effects. Here we experimentally demonstrate the precise(More)
All mutually unbiased bases in dimensions two to five (9&10) 803 M. Limitations on the simulation of non-sparse … (7&8) 669 S.K. Choudhary, Hardy's non-locality and generalized non-local theory (9&10) 859 A. Denney, Finding conjugate stabilizer subgroups in PSL and … (3&4) 282 H. Dinh, Quantum and randomized lower bounds for local search on … (7&8) 636 R.(More)
In the present work, we investigate the quantum thermal entanglement in molecular magnets composed of dimers of spin S, using an Entanglement Witness built from measurements of magnetic susceptibility. An entanglement temperature, Te, is then obtained for some values of spin S. From this, it is shown that Te is proportional to the intradimer exchange(More)
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