Author pages are created from data sourced from our academic publisher partnerships and public sources.

Publications Influence

Realization of the quantum Toffoli gate with trapped ions.

Gates acting on more than two qubits are appealing as they can substitute complex sequences of two-qubit gates, thus promising faster execution and higher fidelity. One important multiqubit operation… Expand

225 4- PDF

Three-Color Entanglement

- A. S. Coelho, F. Barbosa, K. N. Cassemiro, A. S. Villar, M. Martinelli, P. Nussenzveig
- Physics, Medicine
- Science
- 6 November 2009

Entangling Rainbows Quantum mechanical entanglement is at the heart of quantum information processing. In the future, practical systems will contain a network of quantum components, possibly… Expand

143 4- PDF

Quantum state reconstruction of spectral field modes: Homodyne and resonator detection schemes

- F. Barbosa, A. S. Coelho, +4 authors M. Martinelli
- Physics
- 9 October 2013

We revisit the problem of quantum state reconstruction of light beams from the photocurrent quantum noise. As is well-known, but often overlooked, two longitudinal field modes contribute to each… Expand

14 3- PDF

Generation of bright two-color continuous variable entanglement.

- A. S. Villar, L. S. Cruz, K. N. Cassemiro, M. Martinelli, P. Nussenzveig
- Physics, Medicine
- Physical review letters
- 16 June 2005

We present the first measurement of squeezed-state entanglement between the twin beams produced in an optical parametric oscillator operating above threshold. In addition to the usual squeezing in… Expand

165 2- PDF

Realization of universal ion-trap quantum computation with decoherence-free qubits.

Any residual coupling of a quantum computer to the environment results in computational errors. Encoding quantum information in a so-called decoherence-free subspace provides means to avoid these… Expand

64 2- PDF

Extra phase noise from thermal fluctuations in non-linear optical crystals

- A. S. Coelho, J. S. César, K. N. Cassemiro, A. S. Villar, P. Nussenzveig, M. Martinelli
- Physics
- CLEO/Europe - EQEC - European Conference on…
- 11 June 2009

Recent experiments with Optical Parametric Oscillators have shown [1–3] that an unpredicted extra noise on the phase of the fields reduces the level of squeezing or quantum correlations. In some… Expand

20 2- PDF

Continuous variables quantum computation over the vibrational modes of a single trapped ion

- L. Ortiz-Guti'errez, Bruna Gabrielly, L. F. Muñoz, Kaina T. Pereira, J. G. Filgueiras, A. S. Villar
- Physics, Mathematics
- 29 February 2016

Abstract We consider the quantum processor based on a chain of trapped ions to propose an architecture wherein the motional degrees of freedom of trapped ions (position and momentum) could be… Expand

12 2- PDF

Absolute Frequency Measurement of the 40Ca+ 4s 2S1/2 -3d2D5/2 Clock Transition

- M. Chwalla, J. Benhelm, +12 authors P. Laurent
- Physics
- 9 June 2008

We report on the first absolute transition frequency measurement at the 10 -15 level with a single, laser-cooled 40 Ca + ion in a linear Paul trap. For this measurement, a frequency comb is… Expand

74 1- PDF

Scalable continuous-variable entanglement of light beams produced by optical parametric oscillators

- K. N. Cassemiro, A. S. Villar
- Physics
- 17 January 2008

We show that scalable multipartite entanglement among light fields may be generated by optical parametric oscillators OPOs. The tripartite entanglement existent among the three bright beams produced… Expand

23 1- PDF

Beyond spectral homodyne detection: complete quantum measurement of spectral modes of light.

- F. Barbosa, A. S. Coelho, +4 authors A. S. Villar
- Physics, Medicine
- Physical review letters
- 26 August 2013

Spectral homodyne detection, a widely used technique for measuring quantum properties of light beams, cannot retrieve all the information needed to reconstruct the quantum state of spectral field… Expand

19 1- PDF