Extrema of discrete Wigner functions and applications (2008)
Casaccino, Andrea, Galvao, Ernesto F., Severini, Simone
We study the class of discrete Wigner functions proposed by Gibbons et al. [Phys. Rev. A 70, 062101 (2004)] to describe quantum states using a discrete phase-space based on finite fields. We find the...
Classicality in discrete Wigner functions (2005)
Cormick, Cecilia, Galvao, Ernesto F., Gottesman, Daniel, Paz, Juan Pablo, Pittenger, Arthur O.
Gibbons et al. [Phys. Rev. A 70, 062101(2004)] have recently defined a class of discrete Wigner functions W to represent quantum states in a Hilbert space with finite dimension. We show that the only...
Discrete Wigner functions and quantum computational speedup (2004)
In [Phys. Rev. A 70, 062101 (2004)] Gibbons et al. defined a class of discrete Wigner functions W to represent quantum states in a finite Hilbert space dimension d. I characterize a set C_d of states...
Foundations of quantum theory and quantum information applications (2002)
This thesis establishes a number of connections between foundational issues in quantum theory, and some quantum information applications. It starts with a review of quantum contextuality and...
Substituting a qubit for an arbitrarily large number of classical bits (2001)
Galvao, Ernesto F., Hardy, Lucien
We show that a qubit can be used to substitute for an arbitrarily large number of classical bits. We consider a physical system S interacting locally with a classical field phi(x) as it travels...
A feasible quantum communication complexity protocol (2001)
I show that a simple multi-party communication task can be performed more efficiently with quantum communication than with classical communication, even with low detection efficiency $\eta$. The task...
Experimental requirements for quantum communication complexity protocols (2000)
I present a simple two-party quantum communication complexity protocol with higher success rate than the best possible classical protocol for the same task. The quantum protocol is shown to be...
Cloning and quantum computation (2000)
Galvao, Ernesto F., Hardy, Lucien
We discuss how quantum information distribution can improve the performance of some quantum computation tasks. This distribution can be naturally implemented with different types of quantum cloning...