8 papers
Why Quantum Theory?
Lucien Hardy
The usual formulation of quantum theory is rather abstract. In recent work I have shown that we can, nevertheless, obtain quantum theory from five reasonable axioms. Four of these…
Substituting a qubit for an arbitrarily large number of classical bits
Ernesto F. Galvao, Lucien Hardy
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)…
Quantum Theory From Five Reasonable Axioms
Lucien Hardy
The usual formulation of quantum theory is based on rather obscure axioms (employing complex Hilbert spaces, Hermitean operators, and the trace rule for calculating probabilities).…
Can We Obtain Quantum Theory From Reasonable Axioms?
Lucien Hardy
See quant-ph/0101012
Quantum Anti-Cloning
David D. Song, Lucien Hardy
We derive the transformation for the optimal universal quantum anti-cloner which produces two anti-parallel outputs for a single input state. The fidelity is shown to be 2/3 which…
Cloning and quantum computation
Ernesto F. Galvao, Lucien Hardy
We discuss how quantum information distribution can improve the performance of some quantum computation tasks. This distribution can be naturally implemented with different types o…