Brazilian Center for Research in Physics

Rio de Janeiro Brazil

Email: amsouza@cbpf.br

alexandre@amsouza.org

Research Interest

Our research projects are centered on Quantum Information and the Magnetic Resonance technique. We are interested in new experimental methods that can be used to demonstrate new quantum mechanical phenomena, improve magnetic resonance sensitivity and implement quantum computing. We develop the following research lines of investigation:

  • Dynamical decoupling methods for preserving qubits coherence;

  • Design and construction of microresonators for magnetic resonance experiments ;

  • Implementation of quantum computing protocols using the NMR technique and cloud-based quantum computers;

  • Study of new quantum phenomena related to classical and quantum correlations and quantum thermodynamics;

  • Optically detected magnetic resonance with NV-Centers.

Selected Publications

  • Dynamical Decoupling

  1. Robust Dynamical Decoupling for Quantum Computing and Quantum Memory. Phys. Rev. Lett. 106, 240501 (2011)

  2. Robust dynamical decoupling. Phil. Trans. R. Soc. A.3704748–4769

  3. Protected Quantum Computing: Interleaving Gate Operations with Dynamical Decoupling Sequences. Phys. Rev. Lett. 112, 050502 (2014)

  4. Process tomography of Robust Dynamical Decoupling in Superconducting Qubits. Quant. Inf. Proc. 20 237 (2021)

  • Quantum Correlations and Bell's Inequality

  1. Environment-Induced Sudden Transition in Quantum Discord Dynamics. Phys. Rev. Lett. 107, 140403 (2011)

  2. Observation of Environment-Induced Double Sudden Transitions in Geometric Quantum Correlations. Phys. Rev. Lett. 111, 250401 (2013)

  3. Quantum Discord Determines the Interferometric Power of Quantum States. Phys. Rev. Lett. 112, 210401 (2014)

  4. Observation of Time-Invariant Coherence in a Nuclear Magnetic Resonance Quantum Simulator. Phys. Rev. Lett. 117, 160402 (2016)

  5. A scattering quantum circuit for measuring Bell's time inequality: a nuclear magnetic resonance demonstration using maximally mixed states. New Journal of Physics, Volume 13, (2011)

  • Quantum Thermodynamics

  1. Experimental Reconstruction of Work Distribution and Study of Fluctuation Relations in a Closed Quantum System. Phys. Rev. Lett. 113, 140601 (2014)

  2. Irreversibility and the Arrow of Time in a Quenched Quantum System. Phys. Rev. Lett. 115, 190601 (2015)

  3. Reversing the direction of heat flow using quantum correlations. Nature Communications volume 10, Article number: 2456 (2019)

  4. Experimental Characterization of a Spin Quantum Heat Engine. Phys. Rev. Lett. 123, 240601 (2019)

  5. Efficiency of a Quantum Otto Heat Engine Operating under a Reservoir at Effective Negative Temperatures. Phys. Rev. Lett. 122, 240602 (2019)

  6. Experimental validation of fully quantum fluctuation theorems. Phys,Rev. Lett. 127, 180603 (2022) .

  • Quantum Computing

  1. Experimental magic state distillation for fault-tolerant quantum computing. Nature Communications volume 2, Article number: 169 (2011)

  2. An Application of Quantum Annealing Computing to Seismic Inversion Front. Phys. 18 January 2022.

  • Thermal Entanglement

  1. Experimental determination of thermal entanglement in spin clusters using magnetic susceptibility measurements. Phys. Rev. B 77, 104402 (2008)